| titration behavior of individual tyrosine residues of myoglobins from sperm whale, horse, and red kangaroo. | the titration behavior of individual tyrosine residues of myoglobins has been studied by observing the ph dependence of the chemical shifts of czeta and cgamma of these residues in natural abundance of 13c fourier transform nmr spectra (at 15.18 mhz, in 20-mm sample tubes, at 37 degrees) of cyanoferrimyoglobins from sperm whale, horse, and red kangaroo. a comparison of the ph dependence of the spectra of the three proteins yielded specific assignments for the resonance of tyr-151 (sperm whale) a ... | 1976 | 8455 |
| cultivation conditions of the aspergillus terricola mutant producing proteolytic enzyme. | the effect of temperature, aeration and various foam suppressors on the growth of a mutant of aspergillus terricola h-20 and on its production of proteolytic enzymes was studied. a high level of the proteolytic activity (12-15 pu/ml) was found at 28-30 degree c in conditions of aeration with the rate of oxygen dissolution being 0.38-0.86 g of oxygen per litre per hour. synthesis of the enzyme was inhibited by a decrease in temperature to 22-24 degree c, a surplass (1.07 g o2 per litre per hour) ... | 1976 | 12453 |
| the effect of evolution on homologous proteins: a comparison between the chromophore microenvironments of italian water buffalo (bos bubalus, l.) and sperm whale apomyoglobin. | the perturbing effect of guanidium hydrochloride and ph on the molecular structure of water buffalo apomyoglobin has been investigated by circular dichroism in the far and near ultraviolet and by fluorescence. in the wavelength region between 320 and 260 nm the circular dichroic spectrum of the globin is highly structured and the contributions of the aromatic chromophores have been resolved. buffalo apomyoglobin undergoes a structural transition at neutral ph which involves elements of the secon ... | 1978 | 23858 |
| acid and alkaline forms of the higher oxidation state of kangaroo, horse, and sperm whale myoglobin. | myoglobin(iv), the derivative of myoglobin at the formal oxidation state iv, prepared from kangaroo (megaleia rufa), horse, or sperm whale myoglobin, when cooled to liquid nitrogen temperature, assumes acid and alkaline forms with different optical spectra. the essential features of the optical spectra of the acid forms are the same as those of leghemoglobin(iv) and are very similar to those of optical spectra of the red higher oxidation states of catalases and peroxidases. this shows that the c ... | 1978 | 27521 |
| acid bohr effects in myoglobin characterized by proton nmr hyperfine shifts and oxygen binding studies. | proton nmr studies of sperm whale and horse deoxymyoglobin have revealed that both proteins exhibit a single, well defined, ph-induced structural change. the changes in hyperfine shifts are clearly observed not only at the heme peripheral substituents, but also at the proximal histidyl imidazole, which suggest that heme-apoprotein contacts are looser in the acidic than alkaline conformations. the hyperfine shift changes are modulated by a single titratable group with a pk of approx. 5.7 in both ... | 1978 | 31920 |
| co and o2 complexes of soybean leghemoglobins: ph effects upon infrared and visible spectra. comparisons with co and o2 complexes of myoglobin and hemoglobin. | the effects of ph upon infrared spectra [co stretching frequency (vco) region] and visible spectra of the co complexes of soybean leghemoglobins a, c1, and c2, sperm whale myoglobin, and human hemoglobin a are reported. the vco for leghemoglobin--co complexes was 1947.5 cm-1 at neutral ph. at acid ph myoglobin-- and hemoglobin--co complexes developed vco bands at 1966--1968 cm-1, whereas leghemoglobin--co complexes developed vco bands at approximately 1957 cm-1. all pkapp co values determined b ... | 1979 | 34425 |
| near-heme histidine residues of deoxy- and oxymyoglobins. | proton nmr titration curves of the histidine cepsilon-h resonances of the deoxy and oxy forms of human, horse, and sperm whale myoglobins (mb) were determined and compared with the results for the met and azide forms. one extra titrating resonance (h-8) was observed for each deoxy-mb compared with the corresponding met-mb, and a further extra resonance (h-9) was observed for the oxy-mb form. these resonances correspond to the two additional resonances previously described for azide-mb [hayes, m. ... | 1979 | 34431 |
| determinants of the hierarchy of humoral immune responsiveness during ontogeny. | a model system of ontogeny was utilized to investigate the development of humoral immunity in both akr and balb/c mice. lethally irradiated adult mice were reconstituted with syngeneic fetal or neonatal liver. these mice were immunized at various times after reconstitution with a series of eight antigens: the bacteriophages f2, phix-174, and t4; the hapten carrier complexes 2,4 dinitrophenyl-bovine serum albumin and fluorescein-bovine serum albumin; and the small proteins: hen egg lysozyme, sper ... | 1975 | 52670 |
| antibodies against protein antigenic sites that are identical in the homologous protein of the immunized animal. autoreactivity in rabbits of antibodies to sperm-whale myoglobin. | sequence comparisons between the antigenic sites of sperm-whale myoglobin and the corresponding regions in rabbit myoglobin indicate that rabbits make antibodies to regions of the sperm-whale myoglobin molecule which are identical to the corresponding regions in rabbit myoglobin. rabbit myoglobin did not precipitate with antisera to sperm-whale myoglobin. however, it exhibited an extensive cross-reaction as demonstrated by its ability to inhibit the precipitin reaction of sperm-whale myoglobin, ... | 1977 | 71166 |
| prediction and conformation by synthesis of two antigenic sites in human haemoglobin by extrapolation from the known antigenic structure of sperm-whale myoglobin. | the complete antigenic structure of sperm-whale myoglobin was previously determined in our laboratory. by structural analogy with myoglobin, two regions in human haemoglobin were predicted to comprise antigenic sites. one region was on the alpha-chain [alpha-(15-23)] and the other on the beta-chain [beta-(16-23)]. these two regions were synthesized, purified and characterized, and their immunochemistry was studied. each peptide was able specifically to bind considerable amounts of haemoglobin an ... | 1977 | 73374 |
| first consequences of the determination of the entire antigenic structure of sperm-whale myoglobin. | by using the antigenic structure of sperm-whale mb as a model we have established that the antigenicity of its sites is independent of any sequence identities between the injected myoglobin and the mb of the immunized animal. furthermore, the ability to produce in rabbits autoantibodies to rabbit mb and the successful extrapolation of the antigenic structure of sperm-whale mb to human hemoglobin strongly demonstrated that the antigenicity of certain parts of a protein molecule is primarily depen ... | 1978 | 82383 |
| studies of individual carbon sites of proteins in solution by natural abundance carbon 13 nuclear magnetic resonance spectroscopy. strategies for assignments. | natural abundance 13c fourier transform nmr spectra (at 15.18 mhz, in 20-mm sample tubes) of aqueous native proteins yield numerous narrow single carbon resonances of nonprotonated aromatic carbons. techniques for the assignment of these resonances are presented. each technique is applied to one or more of the following proteins: ferricytochrome c from horse heart and candida krusei, ferrocytochrome c and cyanoferricytochrome c from horse heart, lysozyme from hen egg white, cyanoferrimyoglobins ... | 1975 | 169240 |
| optical and magnetic resonance studies of formate binding to horse liver catalase and sperm whale myoglobin. | the binding of formate ion, a substrate for the peroxidatic reaction of catalase, has been investigated by magnetic resonance techniques. comparative studies of formate binding to ferric myoglobin have also been performed. the nuclear magnetic relaxation (nmr) rate of formate and water protons is enhanced by the presence of ferric horse liver catalase. the enhancement is not changed significantly by the addition of cyanide, indicating that water and formate are still bound in the presence of cya ... | 1975 | 169890 |
| solvent denaturation of globular proteins: unfolding by the monoalkyl- and dialkyl-substituted formamides and ureas. | the effects of the monoalkyl and dialkyl-substituted formamide series of denaturants on the native conformation of sperm whale myoglobin, horse heart cytochrome c, and glycera dibranciata (single chain) hemoglobin have been investigated by spectral measurements in the soret region (409 and 422 nm) and optical rotation measurements (265nm). the effectiveness of these two classes of protein denaturants is similar to the other straight-chain compounds of the urea, amide, and alcohol classes, examin ... | 1977 | 189823 |
| isolation and primary structure of adrenocorticotropin from several species of whale. | the isolation of adrenocorticotropin (acth) from fin (balaenoptera physalus), sei (blaenoptera borelis) and sperm (physeter catodon) whale pituitaries is described. their primary structures have been elucidated by the fluorescein isothiocyanate method and revealed to be identical to the structure of the human hormone. fin whale exhibited an identical steroidogenic activity to that of the porcine hormone. | 1978 | 217846 |
| electrostatic effects in myoglobin. application of the modified tanford-kirkwood theory to myoglobins from horse, california grey whale, harbor seal, and california sea lion. | the modified tanford-kirkwood electrostatic theory (shire et al., 1974a) was applied to ferrimyoglobins from the following animal species: sperm whale (physeter catodon), horse, california grey whale (eschrichtius gibbosus), harbor seal (phoca vitulina), and california sea lion (zalophus californianus). computations were made of the overall hydrogen ion titration curves of the proteins, and of ph and ionic strength variations of ionization equilibria for individual groups in the protein, with pa ... | 1975 | 235950 |
| determination of the pk values for the alpha-amino groups of human hemoglobin. | the rate of reaction between alpha-amino groups and cyanic acid was followed at 26 degrees and ionic strength 0.2 m as a function of ph of human hemoglobin ao solutions to determine the pk and the ph-independent second order rate constant, kappa, for these groups in the alpha and beta chains. at a given point in time, the extent of the reaction was determined by employing the beckmann sequencer as a quantitative tool in which the yields of leucine and histidine in the second edman degradation cy ... | 1975 | 237898 |
| nmr studies of hemoproteins. vi. acid-base transitions of ferric myoglobin and its imidazole complex. | 220 mhz proton nmr was applied to the acid-base transition of ferric myoglobin and its imidazole complex. in horse and sperm whale ferric myoglobins: (1) ph-dependent shift of heme-ring methyl signals above p2h 10 was analyzed on the basis of rapid exchange between alkaline and acidic forms by the use of pk value 9.1 of acid-base transition in 1h20 solution; (2) limiting shifts of three methyl signals were reasonably determined for purely alkaline form. for the imidazole complex: (3) a drastic h ... | 1975 | 238653 |
| scanning isoelectric focusing in small density-gradient columns. iv. the use of deuterium oxide for preparing the density gradient and its effects on isoelectric points of proteins. | the use of deuterium oxide as a substitute for sucrose in preparing density gradients for small isoelectrofocusing columns has been investigated. a density gradient was created directly in a 1.5-ml column by free inter-diffusion of three deuterium oxide solutions for 3 min. the resulting deuterium oxide concentration course (as shown by measurement of the refractive-index gradient) had a very high degree of linearity. test runs with beta-lactoglobulin and sperm-whale myoglobin showed that the st ... | 1975 | 239016 |
| nuclear magnetic resonance titration curves of histidine ring protons. human metmyoglobin and the effects of azide on human, horse, and sperm whale metmyoglobins. | four titrating histidine ring c2 and c4 proton resonances are observed in 220 mhz proton nmr spectra of human metmyoglobin as a function of ph. values of ionization constants determined from the nmr titration data using an equation describing a simple proton association-dissociation equilibrium are curves (1) 6.6, (2) 7.0, (3) 5.8, and (4) 7.4. four histidine residues have also been found to be solvent-accessible in human metmyoglobin by carboxymethylation studies (harris, c.m., and hill, r.l. ( ... | 1975 | 240829 |
| evidence for cellular but not serologic cross-reactivity between keyhole limpet hemocyanin and sperm-whale myoglobin. | | 1979 | 314851 |
| resonance raman examination of axial ligand bonding and spin-state equilibria in metmyoglobin hydroxide and other heme derivatives. | resonance raman spectra and excitation profiles have been obtained within the 5700-6300-a absorption band of purified sperm whale metmyoglobin hydroxide (mbiiioh) solutions. a large enhancement occurs for a raman peak at 490 cm-1 which is shown by isotopic substitution of 18o for 16o to be almost purely an fe-o stretch. the fe-o vibration in mbiiioh occurs 5 cm-1 to lower energy than the corresponding vibration at 495 cm-1 in human methemoglobin hydroxide (hbiiioh) [asher, s., vickery, l., schus ... | 1979 | 518843 |
| binding of alkylisocyanides with soybean leghemoglobin. comparisons with sperm whale myoglobin. | the binding of various linear and branched chain alkylisocyanides to soybean leghemoglobin has been studied with respect to association and dissociation kinetics and the results compared with those obtained in parallel on sperm whale and horse heart myoglobins; the linear ligands used (methyl to n-heptyl) cover a greater distribution of chain lengths than hitherto used. the association rate constants are much higher for leghemoglobin than for myoglobin, while the dissociation rates are slower. f ... | 1979 | 574140 |
| prevalence of vesicular exanthema of swine antibodies among feral mammals associated with the southern california coastal zones. | serum-neutralizing antibodies to both vesicular exanthema of swine virus (vesv) and san miguel sea lion virus (smsv) were found in a number of animal species having an association with the southern california coastal zones. california sea lions (zalophus californianus) had antibodies to 9 vesv types (a48, c52, d53, e54, f54, g55, i55, j56, and k56). fur seals (callorhinus ursinus) and elephant seal pups (mirounga angustirostris) were tested for antibodies to 6 vesv types and all were negative. c ... | 1978 | 629463 |
| comparative structural and immunochemical properties of leghaemoglobins. | circular dichroism studies on leghaemoglobins from snake bean, lupin, serradella and other plants show that, in common with soybean (reported earlier) they have a similar overall polypeptide chain conformation and haem environment and orientation. immunochemical studies, on the other hand, suggest that the antigenic determinants on the surface of the leghaemoglobins vary considerably. thus, firstly the alpha-helix content of the leghaemoglobins as a class is very similar (60-65%) and approaches ... | 1976 | 820557 |
| an investigation of north atlantic whales for trichinosis. | in 1971, 81 finback (balaenoptera physalus), 119 sei (b. borealis), two piked (b. acutorostrata), 15 humpback (megaptera novaeangliae) and one sperm whale (physeter catodon) taken in the north atlantic off the newfoundland and nova scotia coasts were examined for the presence of trichinella spiralis. all 218 whales were negative for trichinosis. | 1976 | 933319 |
| effects of the aliphatic carboxylate series of salts on the conformation of proteins. | the effects of the aliphatic acid series of salts, formate, acetate, propionate, butyrate, valarate, and caproate, on the conformation of sperm whale myoglobin, human hemoglobin a, and horse heart cytochrome c were investigated by spectral measurements in the soret region, optical rotation, and intrinsic viscosity measurements. the effectiveness of the aliphatic acid salts as unfolding reagents for proteins is found to increase with increasing hydrocarbon content of the alkyl chains of the salts ... | 1976 | 1009083 |
| protein-metal ion interaction: volume effects produced by the interaction of proteins with metal ions. | the interaction of metal cations with single chain globular proteins produces volume increases, the magnitude of which is determined primarily by the ion and to a lesser extent by the protein. the cations are listed in ascending order of volume change: k(i) less than mg(ii) less than sr(ii) less than ca(ii) less than co(ii) less than ni(ii) less than cd(ii) less than zn(ii) less than cu(ii) less than pb(ii). this sequence held for all cation-protein systems investigated except for cd(ii) which p ... | 1976 | 1053536 |
| kinetic and equilibrium studies of the ligand binding reactions of eight electrophoretic components of sperm whale ferrimyoglobin. | the reactions of eight electrophoretic components of sperm whale ferrimyoglobin with fluoride, azide, and cyanide have been studied. there do not appear to be significant differences in rate constants or equilibrium constants among the various components. we conclude that at ph 7.0 in 0.05 m potassium phosphate these ligand binding kinetics and equilibria are insensitive to the net charge on the protein. the variation of the azide equilibrium constant with ionic strength from mu 0.01 m to 0.11 m ... | 1975 | 1122276 |
| degree of dissociation of apohemoglobin studied by nano-second fluorescence-polarization technique. | a fluorescent dye 1-anilino-8-naphthalene sulfonate was complexed with human apohemoglobin and sperm whale apomyoglobin. nanosecond fluorescence-polarization kinetics were measured for each of these complexes in kc1 solutions to obtain their fluorescence lifetimes and rotational correlation times. the rotational correlation time of apohemoglobin-dye complex was found to be 21 ns, which was about twice that of apomyoglobin-dye complex, 11 ns. these values were constant over an ionic strength rang ... | 1975 | 1138915 |
| the complete amino acid sequence of the major component myoglobin of amazon river dolphin (inia geoffrensis). | the complete amino acid sequence of the major component myoglobin from amazon river dolphin, inia geoffrensis, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. three easily separable peptides were obtained by cleaving the protein with cyanogen bromide at the methionine residues and four peptides were obtained by cleaving the methyl-acetimidated protein with trypsin at the arginine residues. from these peptides over ... | 1975 | 1191640 |
| [the flash-photolysis study of recombination of hemoproteins with carbon monoxide at low temperatures]. | the hemoproteins (sperm whale myoglobin, hemoglobin from larvae of chironomus thummi thummi, bovine hemoglobin) were studied in viscous solvents (saturated sucrose solution, glycerol and water-glycerol solutions) in the temperature range +50 divided by -100 degrees c. at low temperatures the three-phase kinetics of mb recombination with co was observed. the velocities of two "fast" reactions did not depend on ligand concentration. this fact indicates that they are due to a so called cage-effect. ... | 1975 | 1219383 |
| alkyl glucosides as effective solubilizing agents for bovine rhodopsin. a comparison with several commonly used detergents. | the suitability of octyl and decyl-beta-d-glucoside as solubilizing agents for the bovine retinal rod outer segment disc membrane was investigated and compared to that of hexadecyltrimethylammonium bromide, n,n-dimethyldodecylamine oxide, emulphogene bc-720 and digitonin. the properties measured included the thermal stability of rhodopsin, regenerability of bleached rhodopsin by addition of 11-cis-retinal, and the rate of denaturation of bleached rhodopsin as measured by changes in the ultraviol ... | 1976 | 1247624 |
| effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 94-100 (antigenic site 3) of myoglobin. | amino acid substitutions outside protein antigenic sites are very frequently assumed to exert no effect on binding to antiprotein antibodies, especially if these are monoclonal antibodies (mabs). in fact, a very popular method for localization of residues in protein antigenic sites is based on the interpretation that whenever a replacement causes a change in binding to antibody, then that residue will be located in the antigenic site. to test this assumption, mabs of predetermined specificity we ... | 1992 | 1280436 |
| effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 15-22 (antigenic site 1) of myoglobin. | monoclonal antibodies (mabs) of predetermined specificity were prepared by immunizing with a free (i.e., not conjugated to any carrier) synthetic peptide representing region 15-22 (site 1) of sperm whale myoglobin (spmb). the cross-reactions of mb variants with three mabs were studied in order to determine whether such interactions are influenced by substitutions outside the site. finback whale mb, which has no substitutions within region 15-22, showed lower cross-reactivity and relative binding ... | 1992 | 1280437 |
| effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 56-62 (antigenic site 2) of myoglobin. | this work was carried out in order to study the effects of substitutions outside antigenic site 2 of sperm whale myoglobin (spmb) on the reactivity of protein variants with antisite 2 monoclonal antibodies (mabs). a synthetic peptide corresponding to region 56-62 (site 2) of spmb was used as an immunogen in mice in its free form (i.e., without coupling to any carrier) to prepare a panel of mabs whose predetermined specificity is directed, by design, against this region. the binding of three of t ... | 1992 | 1280438 |
| anomalous reversed-phase high-performance liquid chromatographic behavior of synthetic peptides related to antigenic helper t cell sites. | sets of overlapping synthetic peptides for three well characterized proteins (sperm whale myoglobin, hen egg lysozyme, and the circumsporozoite protein from plasmodium falciparum) were prepared and examined by reversed-phase high-performance liquid chromatography (rp-hplc). using retention coefficients to predict the retention time of each peptide, several peptides in each protein set were found that exhibited anomalous behavior (i.e. eluted significantly later than predicted). previous work wit ... | 1992 | 1282129 |
| intramolecular translocation of the protein radical formed in the reaction of recombinant sperm whale myoglobin with h2o2. | a sperm whale myoglobin gene containing multiple unique restriction sites has been constructed in puc 18 by sequential assembly of chemically synthesized oligonucleotide fragments. expression of the gene in escherichia coli dh5 alpha cells yields protein that is identical to native sperm whale myoglobin except that it retains the terminal methionine. site-specific mutagenesis has been used to prepare all the possible tyrosine----phenylalanine mutants of the recombinant myoglobin, including the t ... | 1992 | 1315742 |
| the myoglobin-derived radical formed on reaction of metmyoglobin with hydrogen peroxide is not a tyrosine peroxyl radical. | the reductive cleavage of hydrogen peroxide by metmyoglobin produces a protein-derived, motionally restricted free radical detectable by the spin-trapping epr technique. in order to determine if the detected radical was a peroxyl radical, 17o2 and anoxic conditions were employed. the epr spectra of the metmyoglobin-derived radical adduct detected under nitrogen incubations were identical to those of the oxygenated systems in both intensity and form. no additional hyperfine couplings were detecte ... | 1992 | 1325397 |
| [study of electron transport in heme proteins. x. effect of ph, ionic strength, and zinc ions and the rate of ferricytochrome c reduction by oxymyoglobin from swine heart]. | the rate of the redox reaction between porcine mbo2 and ferri-cyt c at different ionic strengths in the ph range 5-8 has been studied. at low ionic strength (i = 0-0.1) the ph dependence curve was found to have a sigmoid shape with pkeff approximately 5.7, implying the effect of ionization of his-119(gh1) at the "active site" of myoglobin on the kinetics of the process. in this range of ionic strengths the rate of the reaction decreases sharply. the slope of the curve in the coordinates of igkex ... | 1992 | 1331770 |
| matrix-assisted laser desorption using a fast-atom bombardment ion source and a magnetic mass spectrometer. | a conventional fast-atom bombardment (fab) ion source was used to achieve matrix-assisted laser desorption (mald) in a high-mass, double-focusing, magnetic mass spectrometer. the pulsed ion signals generated by irradiation of a mixture of sample and matrix (2,5-dihydroxybenzoic acid) with either a xef excimer laser (353 nm) or a nitrogen laser (337 nm) were recorded with a focal-plane detector. a resolution (full-width at half maximum) of 4500 was achieved at m/z 1347.7 (the peptide substance p) ... | 1992 | 1373978 |
| limited t cell receptor beta-chain usage in the sperm whale myoglobin 110-121/e alpha da beta d response by h-2d congenic mouse strains. | the specificity and tcr gene usage of a panel of sperm whale myoglobin (spwmb)-reactive t cell clones from dba/2 mice have previously been characterized, to study structure-function relationships between components of the ternary complex consisting of ag, tcr, and mhc class ii molecules, whose interaction leads to th cell activation. these dba/2 clones were specific for epitopes within the residue 110 to 121 region of spwmb, in the context of the mixed isotype molecule e alpha da beta d, and exp ... | 1992 | 1382096 |
| high-resolution x-ray structures of pig metmyoglobin and two cd3 mutants: mb(lys45----arg) and mb(lys45----ser). | the structure of pig aquometmyoglobin has been refined to a crystallographic r-factor of 19.8% against x-ray diffraction data between 10- and 1.75-a spacing. the final structural model comprises two molecules of pig myoglobin, 233 water molecules, and two sulfate ions. a water molecule is coordinated to each of the heme iron atoms with an average fe-oh2 bond distance of 2.19 a, and the mean fe-n epsilon (proximal histidine-93) distance is 2.20 a. in contrast to the structure of sperm whale metmy ... | 1992 | 1390659 |
| [comparative analysis of spatial organization of myoglobins. ii. secondary structure]. | an analysis of probability of distribution curves of alpha-helical sites and bends of polypeptide chains of myoglobins in half-water mammals (beaver, nutria, muskrat, otter) carried out in comparison with those of myoglobins of the horse and sperm whale (x-ray diffraction analysis has revealed their tertiary structure) has revealed a coincidence of the secondary structure sites end bends of the chain in the studied respiratory hemoproteins of muscles. despite a considerable number of amino acid ... | 1992 | 1413113 |
| protein dynamics. vibrational coupling, spectral broadening mechanisms, and anharmonicity effects in carbonmonoxy heme proteins studied by the temperature dependence of the soret band lineshape. | in this work we study the temperature dependence of the soret band lineshape of the carbonmonoxy derivatives of sperm whale myoglobin, human hemoglobin, and its isolated alpha and beta subunits. to fit the observed spectral profile we use an analytic expression derived for a system whereby a single electronic transition is coupled to franck-condon active vibrational modes, within the adiabatic and harmonic approximation. the vibronic structure of the spectra arises from the coupling with high fr ... | 1992 | 1420893 |
| [participation of tyrosine residues of myoglobin in the disproportionateness reaction of heme iron (ii) and (iv)]. | by means of the comparison of the constant oxidation reactions of both the myoglobin modified by n-acetylimidazole and the intact myoglobin in the presence of h2o2 or ferrylmyoglobin we characterized the role of the tyrosine residues (tyr) of myoglobin in the synproportionation reaction between heme iron (ii) of one molecule and heme iron (iv)--of another. it was demonstrated that tyr derivatization resulted in the decrease of the velocity of redox interaction between deoxymyoglobin (ii) and fer ... | 1992 | 1421219 |
| 1h-nmr comparative study of the active site in shark (galeorhinus japonicus), horse, and sperm whale deoxy myoglobins. | 1h-nmr spectra of deoxy myoglobins (mbs) from shark (galeorhinus japonicus), horse, and sperm whale have been studied to gain insights into their active site structure. it has been demonstrated for the first time that nuclear overhauser effect (noe) can be observed between heme peripheral side-chain proton resonances of these paramagnetic complexes. val-e11 methyl and his-f8 c delta h proton resonances of these mbs were also assigned from the characteristic shift and line width. the hyperfine sh ... | 1992 | 1429532 |
| the interaction of trolox c, a water-soluble vitamin e analog, with ferrylmyoglobin: reduction of the oxoferryl moiety. | the oxidation of the heme iron of metmyoglobin by h2o2 yields an oxo ferryl complex (feiv = o), similar to compound ii of peroxidases, as well as a protein radical; this high oxidation state of myoglobin is known as ferrylmyoglobin. the interaction of trolox, a water-soluble vitamin e analog, with ferrylmyoglobin entailed two sequential one-electron oxidations of the phenolic antioxidant with intermediate formation of a phenoxyl radical and accumulation of a quinone end product. these oxidation ... | 1992 | 1444470 |
| effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 145-151 (antigenic site 5) of myoglobin. | monoclonal antibodies of predetermined specificity were prepared by immunization with a free (i.e., without coupling to any protein carrier) synthetic peptide representing region 145-151 of sperm whale myoglobin (spmb) and their cross-reactions with eight mb variants were determined. five mbs--bottle-nose dolphin myoglobin (bdmb), pacific common dolphin myoglobin (pdmb), horse myoglobin (hsmb), dog myoglobin (dgmb), and badger myoglobin (bgmb)--have an identical sequence in that region. neverthe ... | 1992 | 1466763 |
| thin-layer microcalorimetric studies of oxygen and carbon monoxide binding to hemoglobin and myoglobin. | a thin-layer gas-solution microcalorimeter has been developed to study the binding reactions of gaseous ligands with ligand binding macromolecules. we have measured the enthalpy of binding oxygen and carbon monoxide to horse myoglobin, human hemoglobin a0 and sperm whale myoglobin in phosphate buffer at ph 7.6, with the enzyme reducing system of hayashi. reactions of human hemoglobin were also done under various buffer conditions in order to elucidate the bohr effect. these binding reactions wer ... | 1992 | 1467445 |
| multinucleated giant cells in primary cultures derived from canine bone marrow--evidence for formation of putative osteoclasts. | mononucleated cells derived from canine bone marrow were maintained in vitro for up to 6 weeks. the culture characteristics and development of these cells were evaluated by histological, ultrastructural and histochemical methods. within 1 week the cells had fused together to form flattened, multinucleated cells. further fusing with one another and other mononucleated cells produced large (diameters more than 300 microns), multinucleated cells which frequently contained more than 50 nuclei per ce ... | 1992 | 1499049 |
| constitutive expression of osteoclast-stimulating activity by normal clonal osteoblast-like cells: effects of parathyroid hormone and 1,25-dihydroxyvitamin d3. | osteoblasts are known to produce osteoclast-stimulating activity (osa). the aim of the current study was to relate the expression of osa to the osteoblastic phenotype and examine its regulation by calciotropic hormones. the study was performed with the normal osteoblastic cell clone crp 10/30 and the preosteoblastic clone crp 4/7. osa was determined with the well described isolated osteoclast pit assay, using sperm whale dentine as substrate. in contrast to previous studies, the assay was carrie ... | 1992 | 1505460 |
| infection with schistosoma mansoni alters th1/th2 cytokine responses to a non-parasite antigen. | schistosoma mansoni infection in the mouse has been shown to be accompanied by a down-regulation in parasite-ag- and mitogen-induced th1 cytokine secretion (il-2 and ifn-gamma) with a simultaneous increase in the production of th2 cytokines (il-4, il-5, and il-10), suggesting a generalized imbalance in lymphocyte function. in the present study, we examined whether infection with s. mansoni would also influence the character of immune responses to a non-parasite ag, sperm whale myoglobin (swmb). ... | 1992 | 1533656 |
| the correct molecular weight of myoglobin, a common calibrant for mass spectrometry. | myoglobins from horse heart muscle, horse skeletal muscle and sperm whale are widely used as calibration standards or test compounds for various mass spectrometric methodologies. in all such cases reported in the literature, a molecular weight value is used (16,950.5 and 17,199, respectively) which is based on the assumption that amino acid 122 in this 153 amino-acid-long protein is asparagine, overlooking a published suggestion that it is aspartic acid instead. since the mass assignment accurac ... | 1992 | 1591398 |
| a novel site-directed mutant of myoglobin with an unusually high o2 affinity and low autooxidation rate. | mutants of sperm whale myoglobin were constructed at position 29 (b10 in helix notation) to examine the effects of distal pocket size on the rates of ligand binding and autooxidation. leu29 was replaced with ala, val, and phe using the synthetic gene and escherichia coli expression system of springer and sligar (springer, b. a., and sligar, s. g. (1987) proc. natl. acad. sci. u. s. a. 84, 8961-8965). structures of the ferric forms of val29 and phe29, and the oxy form of phe29 myoglobin were dete ... | 1992 | 1629229 |
| structural comparison of apomyoglobin and metaquomyoglobin: ph titration of histidines by nmr spectroscopy. | proton nmr spectroscopy was applied to myoglobin in the ferric, water-liganded form (metmbh2o) and the apo form (apomb) to probe the structure and stability of the latter. proteins from sperm whale and horse skeletal muscles were studied to simplify the spectral assignment task. nuclear overhauser effects and the response of chemical shifts to variations of ph were used as indicators of residual native holoprotein structure in the apoprotein. the investigation was focused in the histidine side c ... | 1992 | 1633160 |
| electron transfer between horse ferritin and ferrihaemoproteins. | reactions of reduced horse spleen ferritin with horse and saccharomyces cerevisiae ferricytochromes c, cow ferricytochrome b5, sperm-whale metmyoglobin and pseudomonas aeruginosa ferricytochrome c-551 were investigated by u.v.-visible spectrophotometry. in all cases the reduced ferritin reduced the ferrihaemoproteins. the rate of reduction varied from less than 0.2 m-1.s-1 for metmyoglobin to 1.1 x 10(3) m-1.s-1 for horse ferricytochrome c (0.1 m-phosphate buffer, ph 7.4, at 25 degrees c). we co ... | 1991 | 1654893 |
| inhibitory effects of the bone-derived growth factors osteoinductive factor and transforming growth factor-beta on isolated osteoclasts. | demineralized bone matrix contains a number of growth factors for osteoblast-like cells. two of these, the novel glycoprotein osteoinductive factor (oif) and transforming growth factor-beta (tgf beta), act together to cause ectopic bone formation in vivo. since oif, like tgf beta, is likely released from bone when the matrix is resorbed, we examined the effects of homogeneous oif and tgf beta on osteoclast function. osteoclast function was tested in isolated avian osteoclasts and was measured in ... | 1990 | 1693566 |
| insertion of myoglobin t-cell epitopes into the escherichia coli alkaline phosphatase. | we are interested in antigen processing mechanisms of antigen-presenting cells, and to what extent the susceptibility of protein antigens to degradation contributes to immunogenicity. understanding the biochemistry of antigen processing may be essential for reliable prediction of t-cell epitopes and for the design of vaccines that are optimized for t-cell priming. to examine possible effects of protein structural context on antigen presentation, we used genetic engineering techniques to insert h ... | 1990 | 1714095 |
| antigen processing by endosomal proteases determines which sites of sperm-whale myoglobin are eventually recognized by t cells. | this study reports an identification of the major processing products of an exogenous protein antigen, viz, sperm-whale myoglobin, as obtained after cell-free processing with partially purified macrophage endosomes. it is demonstrated that such a system yields fragments that are indistinguishable by high performance liquid chromatography analysis from those generated after uptake of myoglobin inside live macrophages. the concerted action of the endosomal proteases cathepsin d and cathepsin b can ... | 1991 | 1716206 |
| limitations in plasticity of the t-cell receptor repertoire. | how constrained is t-cell recognition? is a truncated t-cell receptor (tcr) repertoire, missing half of its v beta components (where v indicates variable), still broad enough to produce an antigen-specific t-cell response to all determinants? these questions can be answered for certain t-cell antigenic determinants whose response in the wild type is limited to specific gene segments. our results show that mice with such a deletion in their tcr v beta genes (v beta truncated haplotype, va beta) a ... | 1991 | 1719532 |
| differential additions to the myoglobin prosthetic heme group. oxidative gamma-meso substitution by alkylhydrazines. | the oxidative reaction of equine myoglobin with alkylhydrazines results primarily in introduction of the alkyl group at the sterically hindered gamma-meso position. the gamma-meso adducts formed with ethyl- and n-butylhydrazine have been isolated and unambiguously identified. with high pressure liquid chromatography, evidence for the formation of similar adducts with methyl- and n-propylhydrazine but not tert-butyl-, 2,2,2-trifluoroethyl-, or 2-phenylethylhydrazine has also been obtained. the ga ... | 1991 | 1850746 |
| relative-residue surface-accessibility patterns reveal myoglobin and catalase similarity. | a novel sliding-window search method using relative-residue surface-accessibility patterns identified extensive, but unsuspected, structural similarity over a 3-helix region in the c-terminus of the evolutionarily unrelated proteins sperm-whale myoglobin and beef liver catalase. this clear example of structural similarity between non-homologous proteins highlights the importance of relative-residue surface-accessibility patterns in understanding the local folded structure in proteins. | 1991 | 1959649 |
| distal and proximal ligand interactions in heme proteins: correlations between c-o and fe-c vibrational frequencies, oxygen-17 and carbon-13 nuclear magnetic resonance chemical shifts, and oxygen-17 nuclear quadrupole coupling constants in c17o- and 13co-labeled species. | we have obtained the oxygen-17 nuclear magnetic resonance (nmr) spectra of a variety of c17o-labeled heme proteins, including sperm whale (physeter catodon) myoglobin, two synthetic sperm whale myoglobin mutants (his e7----val e7; his e7----phe e7), adult human hemoglobin, rabbit (oryctolagus cuniculus) hemoglobin, horseradish (cochlearia armoracia) peroxidase (e.c. 1.11.1.7) isoenzymes a and c, and caldariomyces fumago chloroperoxidase (e.c. 1.11.1.10), in some cases as a function of ph, and ha ... | 1991 | 2001365 |
| 1h nmr resonance assignments in a paramagnetic heme protein by two-dimensional spectroscopy: heme resonances in equine met-azido myoglobin. | specific heme protons for the majority of resonances in the downfield resolved region of equine met-azido myoglobin have been assigned using solely the two-dimensional 1h nmr experiments noesy and cosy. metazido myoglobin provides a useful test case for the applicability of these techniques to paramagnetic proteins for the following reasons. first met-azido myoglobin is a mixed spin-state protein, with significantly shorter relaxation times and broadened lines relative to pure low-spin systems ( ... | 1991 | 2018499 |
| contributions of residue 45(cd3) and heme-6-propionate to the biomolecular and geminate recombination reactions of myoglobin. | overall association and dissociation rate constants were measured at 20 degrees c for o2, co, and alkyl isocyanide binding to position 45 (cd3) mutants of pig and sperm whale myoglobins and to sperm whale myoglobin reconstituted with protoheme ix dimethyl ester. in pig myoglobin, lys45(cd3) was replaced with arg, his, ser, and glu; in sperm whale myoglobin, arg45(cd3) was replaced with ser and gly. intramolecular rebinding of no, o2, and methyl isocyanide to arg45, ser45, glu45, and lys45(native ... | 1991 | 2029516 |
| control and recognition of anionic ligands in myoglobin. | equilibrium and kinetic experiments on site-directed mutants of a synthetic sperm whale myoglobin (mb) gene have been performed. results on the reactivity on both ferric and ferrous wild type and mutants mb's are presented. analysis of ligand binding to his (e7) val and his (e7) val-thr (e10) arg mutants compared to wild-type sperm whale, horse and aplysia limacina mb's, shows that the introduction of an arginyl residue at the topological position e10 greatly enhances the stability of the variou ... | 1991 | 2037047 |
| resonant recognition model and protein topography. model studies with myoglobin, hemoglobin and lysozyme. | this study describes the further extension of the resonant recognition model for the analysis and prediction of protein--protein and protein--dna structure/function dependencies. the model is based on the significant correlation between spectra of numerical presentations of the amino acid or nucleotide sequences of proteins and their coded biological activity. according to this physico-mathematical method, it is possible to define amino acids in the sequence which are predicted to be the most cr ... | 1991 | 2040273 |
| fluorescence study of the conformational properties of myoglobin structure. 2. ph- and ligand-induced conformational changes in ferric- and ferrousmyoglobins. | tryptophanyl fluorescence of high-spin and low-spin complexes of sperm whale ferric- and ferrousmyoglobins, met-, azide- and cyanomyoglobins and deoxy-, oxy- and carboxymyoglobins has been studied in the ph range 2.5-13. the ph-dependent fluorescence of sperm whale metmyoglobin acylated at the n-terminal alpha-amino group by methylisothiocyanate and of bovine metmyoglobin, which contains invariant trp7 and trp14 but lacks tyr151, have also been examined. drastic changes in the fluorescence were ... | 1991 | 2040284 |
| ultraviolet resonance raman and absorption difference spectroscopy of myoglobins: titration behavior of individual tyrosine residues. | the uv resonance raman spectra of horse and sperm whale myoglobin excited at 240 nm show bands between 600 and 1700 cm-1 which derive from tyrosyl and tryptophyl residues. no significant contribution from phenylalanine and peptide backbone vibrations occurs at this excitation wavelength. we examine the ph dependence of the uv resonance raman and uv absorption difference spectra of these myoglobins to correlate the local protein environment of the tyrosyl residues as given by the protein crystal ... | 1991 | 2043634 |
| protein dynamics. comparative investigation on heme-proteins with different physiological roles. | we report the low temperature carbon monoxide recombination kinetics after photolysis and the temperature dependence of the visible absorption spectra of the isolated alpha sh-co and beta sh-co subunits from human hemoglobin a in ethylene glycol/water and in glycerol/water mixtures. kinetic measurements on sperm whale (physeter catodon) myoglobin and previously published optical spectroscopy data on the latter protein and on human hemoglobin a, in both solvents, (cordone, l., a. cupane, m. leone ... | 1991 | 2049528 |
| inhibition of bone resorption by inorganic phosphate is mediated by both reduced osteoclast formation and decreased activity of mature osteoclasts. | high concentrations of inorganic phosphate (pi) are known to inhibit bone resorption, although the mechanism(s) underlying this effect is unclear. to investigate whether pi can inhibit the formation of osteoclasts we studied the effects of changes in pi concentration between 1 and 4 mm on osteoclast-like cell formation in 1 week cultures of mouse bone marrow. osteoclast-like cells were identified by multinuclearity, positive staining for tartrate-resistant acid phosphatase (trap), and contractio ... | 1991 | 2068953 |
| characteristics of peptides which compete for presented antigen-binding sites on antigen-presenting cells. | the t cell recognition of globular protein antigens requires the cell surface presentation of the protein by ia-expressing antigen-presenting cells (apc). the mechanisms by which apc function remain to be elucidated. to gain a better understanding of association of antigen with apc surfaces, a large panel of peptides of diverse physicochemical properties was assayed for the ability to compete with presented antigen for binding sites on the apc surface. competition was measured by the ability of ... | 1990 | 2162778 |
| the conformation-sensitive immunoassay: a membrane based elisa system for identifying antibodies sensitive to alterations of protein conformation. | a conformation-sensitive immunoassay (csi) has been developed for identification of antibodies that are sensitive to alterations in protein conformation. the method involves covalently coupling proteins to an activated hydrophilic membrane support. the membrane bound proteins are then treated under conditions known to alter protein conformation, immobilized in a non-native state via additional covalent interactions with the support, and subsequently probed using conventional elisa techniques. th ... | 1990 | 2166235 |
| comparison of the dynamics of myoglobin in different crystal forms. | crystals have been grown of "sperm whale" myoglobin produced in escherichia coli from a synthetic gene and the structure has been solved to 1.9 a resolution. because of a remaining initiator methionine, this protein crystallizes in a different space group from native sperm whale myoglobin. the three-dimensional structure of the synthetic protein is essentially identical to the native sperm whale protein. however, the crystallographic b-factors for parts of the molecule are quite different in the ... | 1990 | 2180490 |
| crystal structure of myoglobin from a synthetic gene. | crystals have been grown of myoglobin produced in escherichia coli from a synthetic gene, and the structure has been solved to 1.9 a resolution. the space group of the crystals is p6, which is different from previously solved myoglobin crystal forms. the synthetic myoglobin is essentially identical to myoglobin isolated from sperm whale tissue, except for the retention of the initiator methionine at the n-terminus and the substitution of asparagine for aspartic acid at position 122. superpositio ... | 1990 | 2199973 |
| transient spectroscopy of the reaction of cyanide with ferrous myoglobin. effect of distal side residues. | the reaction of cyanide metmyoglobin with dithionite conforms to a two-step sequential mechanism with formation of an unstable intermediate, identified as cyanide bound ferrous myoglobin. this reaction was investigated by stopped-flow time resolved spectroscopy using different myoglobins, i.e. those from horse heart, aplysia limacina buccal muscle, and three recombinant derivatives of sperm whale skeletal muscle myoglobin (mb) (the wild type and two mutants). the myoglobins from horse and sperm ... | 1990 | 2229052 |
| the effects of amino acid substitution at position e7 (residue 64) on the kinetics of ligand binding to sperm whale myoglobin. | association and dissociation rate constants were measured for o2, co, and alkyl isocyanide binding to a set of genetically engineered sperm whale myoglobins with site-specific mutations at residue 64 (the e7 helical position). native his was replaced by gly, val, leu, met, phe, gln, arg, and asp using the synthetic gene and expression system developed by springer and sligar (springer, b. a., and sligar, s. g. (1987) proc. natl. acad. sci. u.s.a. 84, 8961-8965). the his64----gly substitution prod ... | 1990 | 2303446 |
| x-ray crystal structure of a recombinant human myoglobin mutant at 2.8 a resolution. | we have grown crystals in trigonal space group p3(2)21 of a mutant human myoglobin, aquomet form, in which lysine at position 45 has been replaced by arginine and cysteine at position 110 has been replaced by alanine. suitable crystals of native recombinant human myoglobin have not been obtained. we have used the molecular replacement method to determine the x-ray crystal structure of the mutant at 2.8 a resolution. at the present stage of refinement, the crystallographic r-value for the model, ... | 1990 | 2342104 |
| conformational free energy of armadillo metmyoglobin. | the conformational free energy of armadillo metmyoglobin was examined over a ph range of 4.4-8.0 and a guanidinium chloride concentration of 0-2.3 m. for isothermal unfolding at 25 degrees essentially the same value was obtained for the conformational free energy from all the data: 27 +/- 2 kj/mol. these data suggest that the armadillo has the least stable metmyoglobin of any mammal thus far examined. the cooperativity of the unfolding with respect to denaturant is considerably less than for oth ... | 1990 | 2354875 |
| high-resolution study of the three-dimensional structure of horse heart metmyoglobin. | the three-dimensional structure of horse heart metmyoglobin has been refined to a final r-factor of 15.5% for all observed data in the 6.0 to 1.9 a resolution range. the final model consists of 1242 non-hydrogen protein atoms, 154 water molecules and one sulfate ion. this structure has nearly ideal bonding and bond angle geometry. a luzzati plot of the variation in r-factor with resolution yields an estimated mean co-ordinate error of 0.18 a. an extensive analysis of the pattern of hydrogen bond ... | 1990 | 2359126 |
| hemolytic plaque inhibition by synthetic antigenic peptides of sperm whale myoglobin. | we have investigated the systemic antibody response to sperm whale myoglobin (swmb) antigenic sites in three strains of inbred mice using an inhibition of plaque assay. sperm whale myoglobin was attached to sheep red blood cells (srbc) via rabbit anti-srbc fab' fragments. inhibition of lysis was obtained with synthetic peptides representing the purported five antigenic sites but not with a peptide whose sequence was unrelated to swmb and synthetic peptides of swmb from outside the antigenic site ... | 1985 | 2415451 |
| the antibody response to myoglobin--i. systematic synthesis of myoglobin peptides reveals location and substructure of species-dependent continuous antigenic determinants. | sets of peptides representing all the possible hepta-, octa-, nona- and decapeptides of sperm whale myoglobin were synthesized. an elisa method was used to detect the ability of antibodies, present in antisera raised against native sperm whale myoglobin, to bind to these peptides. antisera made in two species were compared. it was found that the peptides recognized by the antibodies were a function of the species in which the antiserum was prepared and of the individual outbred member of that sp ... | 1986 | 2427938 |
| non-responsiveness to a foot-and-mouth disease virus peptide overcome by addition of foreign helper t-cell determinants. | study of the immune response to synthetic antigens has shown that uncoupled peptides can realize their potential as vaccines only if they contain domains that react with helper t-cell receptors and ia antigens in addition to antibody binding sites. here we consider whether genetically restricted non-responsiveness to an uncoupled peptide could be overcome by synthesizing a peptide with an additional helper t-cell epitope from a different protein. we demonstrate that h-2d mice, which are non-resp ... | 1987 | 2444892 |
| influences of antigen processing on the expression of the t cell repertoire. evidence for mhc-specific hindering structures on the products of processing. | two lines of evidence in the current study indicate that antigen processing is a major factor, in addition to mhc binding and t cell repertoire, that determines ir gene responsiveness and epitope immunodominance. first, immunization with synthetic peptides of myoglobin sequences revealed new reactivities that had not appeared after priming with native myoglobin. for example, b10.s mice (h-2s) immune to equine myoglobin predominantly responded to peptide 102-118, whereas there was little, if any, ... | 1988 | 2456373 |
| t cell response to myoglobin: a comparison of t cell clones in high-responder and low-responder mice. | mice carrying the h-2b haplotype (e.g., inbred strains c57bl/6 and c57bl/10) are low responders to sperm whale myoglobin when tested in the t cell proliferation assay. their response is improved by the removal of the ly-2+ cells from the lymph node population, but it still remains significantly lower than that of cells cells from high-responder strains (e.g., dba/2, h-2d). to determine whether t cells from the low and high-responder mice recognize the same or different epitopes on the immunizing ... | 1988 | 2458940 |
| helper t-cell determinants in vaccine design. | mice belonging to the h-2d haplotype do not respond to the 141-160 peptide of foot-and-mouth disease virus protein vp1. however, when defined 'foreign' helper t-cell determinants from ovalbumin or sperm whale myoglobin are added they do respond. these observations are likely to have important implications for the design of peptide vaccines. | 1989 | 2476143 |
| metal affinity precipitation of proteins. | proteins containing multiple surface-accessible histidine residues can be precipitated using small quantities of bis-copper chelates. the chelates serve to crosslink the proteins, presumably via the accessible histidines, leading to the formation of large, insoluble complexes. when excess copper chelate is used to carry out the precipitation, the resulting precipitate has a stoichiometry of 1:1 copper:accessible histidine. the precipitation is analogous to antibody-antigen precipitin reactions a ... | 1989 | 2508699 |
| ligand and proton exchange dynamics in recombinant human myoglobin mutants. | site-specific mutants of human myoglobin have been prepared in which lysine 45 is replaced by arginine (k45r) and aspartate 60 by glutamate (d60e), in order to examine the influence of these residues and their interaction on the dynamics of the protein. these proteins were studied by a variety of methods, including one and two-dimensional proton nuclear magnetic resonance spectroscopy, exchange kinetics for the distal and proximal histidine nh protons as a function of ph in the met cyano forms, ... | 1989 | 2544737 |
| electron spin resonance spectrum of tyr-151 free radical formed in reactions of sperm whale metmyoglobin with ethyl hydroperoxide and potassium irridate. | a five-line esr spectrum was observed at room temperature in reactions of sperm whale metmyoglobin with ethyl hydroperoxide (etooh) at ph 9.5 and with potassium irridate at ph's 7.0 and 9.5. a spectrum with the same g value and hyperfine splitting constant appeared in a reaction of sperm whale apomyoglobin with potassium irridate and was assigned to a tyrosyl radical on the basis of optical spectrum data obtained under the same reaction conditions. it was concluded that this radical arose from t ... | 1989 | 2556963 |
| piezoelectricity in cementum, dentine and bone. | unlike the dental hard tissues, bone remodels when subjected to orthodontic forces. bone is also piezoelectric (generates a surface electrical charge upon application of force). in dentine and cementum from sperm whale teeth (which gave samples of sufficient size), the existence and magnitude of piezoelectricity were examined and compared with human bone. both dental tissues were found to be piezoelectric with coefficients of 0.027 and 0.028 pc/n, respectively; the coefficient of human bone was ... | 1989 | 2597044 |
| gas-phase sequencing after electroblotting on polyvinylidene difluoride membranes assigns correct molecular weights to myoglobin molecular weight markers. | commercially available polypeptide marker kits containing peptides generated by cyanogen bromide cleavage of either horse heart myoglobin or sperm whale myoglobin have been investigated by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (sds-page), followed by electroblotting on polyvinylidene difluoride membranes, and gas-phase sequencing. it could be shown that the molecular weights assigned to the sds-page bands by the companies are incorrect. arranged in descending order, the mar ... | 1989 | 2619034 |
| studies of the clear zone of osteoclasts: immunohistological aspects of its form and distribution. | bone marrow cells isolated from long bones of a ddy mouse were cultured on sperm whale dentin and examined by light, scanning and transmission electron microscopy. the osteoclasts in vitro showed essentially the same ultrastructures as in vivo. the distribution of actin in the osteoclasts was examined by an indirect immunofluorescent antibody method, which revealed a wide ring-shaped area under the fluorescence microscope. transmission electron microscopy showed that the ring-shaped area corresp ... | 1989 | 2631920 |
| discrimination between oxygen and carbon monoxide and inhibition of autooxidation by myoglobin. site-directed mutagenesis of the distal histidine. | sperm whale myoglobin mutants were constructed using site-directed mutagenesis to replace the highly conserved distal histidine residue (his(e7)-64). his-64 was substituted with gly, val, phe, cys, met, lys, arg, asp, thr, and tyr, and all 10 mutant proteins expressed to approximately 10% of the total soluble cell protein in escherichia coli as heme containing myoglobin. with the exception of his-64----tyr, which did not form a stable oxygen (o2) complex, all mutant proteins could be reduced and ... | 1989 | 2644279 |
| [amino acid sequence of ondatra myoglobin (ondatra zibethica). characteristic features of myoglobins from semiaquatic animals]. | based on the amino acid composition of globin, amino acid analysis and n-terminal sequencing of peptides as well as a comparative analysis of the primary structure of beaver, coypu rat and otter myoglobins with the use of the fingerprinting technique, the amino acid sequence of the major component of ondatra myoglobin including 153 amino acid residues was reconstructed. the results of a comparative analysis of the primary structure of myoglobin and the peculiarities of the functional morphology ... | 1989 | 2675985 |
| the bone marrow-derived stromal cell lines mc3t3-g2/pa6 and st2 support osteoclast-like cell differentiation in cocultures with mouse spleen cells. | after our previous report that osteoclast-like multinucleated cells (mncs) were formed in response to 1 alpha,25-dihydroxyvitamin d3 [1 alpha,25-(oh)2d3] in cocultures of mouse spleen cells and osteoblast-rich populations freshly isolated from fetal mouse calvariae, we examined whether such primary osteoblast-like cells can be replaced by established cell lines in inducing osteoclast-like cell formation. we first used two clonal cell lines simultaneously established from newborn mouse calvariae. ... | 1989 | 2676473 |
| comparative oxygen affinity of fish and mammalian myoglobins. | myoglobins from rat, coho salmon (oncorhynchus kisutch), buffalo sculpin (enophrys bison) hearts, and yellowfin tuna (thunnus albacares) red skeletal muscle were partially purified and their o2 binding affinities determined. commercially prepared sperm whale myoglobin was employed as an internal standard. tested at 20 degrees c, myoglobins from salmon and sculpin bound o2 with lower affinity than myoglobins from the rat or sperm whale. oxygen binding studies at 12 degrees c and 37 degrees c sugg ... | 1989 | 2760286 |
| protozoan myoglobin from paramecium caudatum. its unusual amino acid sequence. | a protozoan myoglobin (or monomeric hemoglobin) was isolated from paramecium caudatum, and its complete amino acid sequence determined. it consists of 116 amino acid residues with a molecular mass of 12,565 daltons, this being much smaller than sperm whale myoglobin by 37 residues and even smaller than a bacterial hemoglobin from vitreoscilla by 30 residues in terms of the monomer unit. a computer search showed no notable sequence homology with other hemoproteins. it contains two histidine resid ... | 1989 | 2769763 |
| kinetic study of the slow cyanide binding to glycera dibranchiata monomer hemoglobin components iii and iv. | compared to other monomeric heme proteins and the heme peroxidases, the glycera dibranchiata monomer hemoglobin components iii and iv exhibit very slow cyanide binding kinetics. this is agreement with the previously reported behavior of component ii. similar to component ii, components iii and iv have been studied under pseudo-first-order conditions at ph 6.0, 7.0, 8.0, and 9.0 by using a 100-250-fold excess of potassium cyanide at each ph. at 20 degrees c with micromolar protein concentrations, ... | 1989 | 2775755 |
| osteoclast-like cells form in long-term human bone marrow but not in peripheral blood cultures. | transplantation studies have suggested that peripheral blood mononuclear cells contain precursors for osteoclasts. thus we tested the capacity of peripheral blood monocytes to form osteoclasts in long-term culture. we have reported previously that mononuclear cells from feline, baboon, and human marrow form osteoclast-like cells in long term cultures. further, the formation of these cells is increased in response to bone resorption stimulatory agents such as pth, interleukin 1, and transforming ... | 1989 | 2783589 |