PMID(sorted descending)
comparison of two ferredoxins from rhodospirillum rubrum as electron carriers for the native coupling the reducing power of illuminated chloroplasts to the nitrogenase from photosynthetically grown rhodospirillum rubrum cells, one of the native ferredoxins. fdi, was found to be three times more effective than fdii.1975803490
generation of electric potential by reaction center complexes from rhodospirillum rubrum. 1975803460
[photoinduced liberation of hydrogen by bacteria, algae and higher plants]. 1975803442
primary structure of a high potential, four-iron-sulfur ferredoxin from the photosynthetic bacterium rhodospirillum tenue.the amino acid sequence of a high oxidation-reduction potential iron-sulfur protein (hipip) isolated from the purple photosynthetic bacterium rhodospirillum tenue has been determined. this is the smallest of the hipip's, containing 63 residues, with only 3 residues apparently conserved in addition to the 4 cluster-binding cysteines. a minimum of four internal genetic gaps is postulated to align tenue high potential iron-sulfur protein with the previously known proteins. it is the most divergent ...1979762147
dna homology studies on nocardia and rhodococcus strains.the genetic homogeneity of nocardia amarae, nocardia autotrophica and rhodococcus strains and the relationship among these groups of microorganisms have been studied using the dna reassociation method. strains belonging to n. amarae and n. autotrophica form genetically homogeneous groups. distinct differences have been found out among rhodococcus strains.1978749779
immunogenicity of methyl esters of nocardomycolic acids.immunogenicity of methyl esters of fatty acids of nocardiae (nocardia (nocardia asteroides atcc 19247, n, brasiliensis n318 and n. caviae n231) was studied. the rabbit antisera obtained against the lipid fractions reacted in the complement fixation test (cf) and in the pash sive cutaneous anaphylaxis test (pca). the results of absorption experiments witt separated fractions of fatty acids esters indicate that the antisera showed activity againsmethyl esters of nocardomycolic acids.1978749777
inactivation of ribulosebisphosphate carboxylase by modification of arginyl residues with phenylglyoxal.phenylglyoxal rapidly and completely inactivates spinach and rhodospirillum rubrum ribulosebisphosphate carboxylases. inactivation exhibits pseudo-first-order kinetics and a reaction order of approximately one for both enzymes, suggesting that modification of a single residue per protomeric unit suffices for inactivation. loss of enzymic activity is directly proportional to incorporation of [14c]phenylglyoxal until only 30% of the initial activity remains. for both enzymes, extrapolation of inco ...1978728421
purification of (4fe-4s)1--2--ferredoxins (high-potential iron--sulfur proteins) from bacteria. 1978713842
structural studies on the d-arabinose-containing lipid a from rhodospirillum tenue 2761.structural studies carried out on the isolated free lipid a of rhodospirillum tenue 2761 revealed a new type of structure for this lipid. the lipid a backbone of 1',6-linked glucosamine disaccharide (central disaccharide) is substituted by three different sugar residues: the non-reducing end of the disaccharide by 4-amino-4-deoxy-l-arabinose 1-phosphate and its reducing end glycosidically by d-arabinofuranose 1-phosphate; further, the reducing glucosamine of the disaccharide is branched to a thi ...1978639795
quantum yield and image contrast of bacteriochlorophyll monolayers in photoelectron microscopy.the photoelectron quantum yield spectrum of bacteriochlorophyll agg (bchl a ) from rhodospirillum rubrum was determined in order to evaluate the possibility of mapping photoreceptor distribution and organization in bacterial chromatophores. the quantum yield is on the order of 1 x 10(-3) electrons/incident photon at 180 nm and decreases to 2.5 x 10(-5) electrons/incident photon at 230 nm. photoelectron micrographs confirm the high contrast predicted between monolayers of bchl a against a lipid b ...1978630040
direct measurement of pure absorbance spectra of living phototrophic microorganisms.the pure absorbance of turbid cell suspensions of various phototrophic microorganisms were determined by collecting the scattered light. a conventional spectrophotometer was used, equipped with an intergrating sphere as receiver unit, which allowed precise measurements of the absorbance in the range from zero to 0.1. in the wavelength range 300--1100 nm, where photosynthesis occurs, light scattered only once by a bacterial cell retains predominantly the forward direction. this allows measurement ...1978626755
biological activities of lipopolysaccharides and lipid a from rhodospirillaceae.the lipopolysaccharides and free lipid a from several strains of rhodospirillaceae were assayed comparatively with those of enterobacteriaceae in a number of biological tests. free lipid a's from rhodopseudomonas gelatinosa and rhodospirillum tenue exhibited strong serological cross-reactions with each other and with free lipid a from salmonella. lipid a's from rhodopseudomonas viridis and rhodopseudomonas palustris, although cross-reacting with each other, did not do so with either the lipid a ...1977558961
[effect of formate on the respiration of different microorganisms].the cells of methylotrophic bacteria (achromobacter parvulus 1, pseudomonas methylica 2 and 20, ps. fluorescens 45, ps. oleovorans 52) and candida methylica 101 grown in a medium with methanol take up oxygen in the presence of formiate. a. parvulus is most resistant to formiate (km = 2.3 +/- 0.5) x 10(-3) m; ki = 4 x 10(-1) m). when grown on cn substrates, these microorganisms cannot oxidize formiate (with an exception of a. parvulus). formiate also serves as a respiration substrate for e. coli ...1979481274
proteins exposed at the surface of chromatophores of rhodospirillum rubrum: the orientation of isolated chromatophores.the exposure of proteins at the surface of isolated chromatophores (i.e., the cytoplasmic face of intracytoplasmic membranes) of rhodospirillum rubrum was studied by proteolysis as well as by enzymatic iodination with 125i. analyses were performed after polyacrylamide gel electrophoresis of chromatophore proteins solubilized with sodium dodecyl sulfate. reversible light induced proton uptake by partially digested chromatophores was used as a criterion for the integrity of the permeability barrie ...1978418810
the photoproduction of h2 and nh4 fixed from n2 by a derepressed mutant of rhodospirillum rubrum.a mutant of rhodospirillum rubrum has been isolated, after mutagenesis with nitrosoguanidine, which is characterized by its inability to grow in the light on malate-minimal media with exogenous ammonia or alanine, poor growth on glutamine and vigorous growth on glutamate. this mutant produces low levels of a key nh+4 assimilation enzyme, glutamate synthase (nadph-dependent). it also exhibits significant derepression of nitrogenase biosynthesis in the presence of ammonia or alanine, being 15% der ...1978418808
modification of rhodospirillum rubrum ribulose bisphosphate carboxylase with pyridoxal phosphate. 2. stoichiometry and kinetics of inactivation.rhodospirillum rubrum ribulose bisphosphate carboxylase contains two high affinity binding sites for pyridoxal phosphate and two catalytic sites per dimer. however, pyridoxal phosphate binding at only one site is sufficient for inactivation of both catalytic sites. in the presence of 20 mm bicarbonate, 10 mm magnesium, and pyridoxal phosphate, the rates of inactivation and schiff base formation are pseudo-first-order and show saturation kinetics. these observations provide additional evidence th ...1978418800
bacteriochlorophyll-protein complexes from the light-harvesting antenna of photosynthetic bacteria. 1978418797
[intermediate states formed during discharge separation in the reaction centers of rhodospirillum rubrum in the presence of a low-redox potential].the intermediate short-lived states arising in reaction centre preparations (rc) of purple bacterium rhodospirillum rubrum are investigated under the conditions of low redox potential. excitation by 353 and 530 nm laser pulses produced two states characterized by optical absorption changes in the range of 350--650 nm and lifetimes: 10--30 ns for the first state and 2.5 +/- 0.5 microseconds for the second one. the first state is similar to the state pf, described previously by parson et al. for r ...1978418326
biochemical identification of a tryptophan auxotroph in rhodospirillum rubrum.a tryptophan auxotroph of aerobically grown rodospirillum rubrum was isolated after mutagenesis and replica plating. the mutant grows on tryptophan or indole, accumulates indole glycerol phosphate, lacks the capacity to convert indole glycerol phosphate to indole glycerol phosphate to indole, and finally is defective in photosynthetic growth. the strain is, therefore, analogous to a trp a mutant which is defective in the alpha-subunit structural gene of tryptophan synthetase.1978417790
measurement by a flow dialysis technique of the steady-state proton-motive force in chromatophores from rhodospirillum rubrum. comparison with phosphorylation potential.1. in the light a transmembrane electrical potential of 100 mv has been estimated to occur in chromatophores from rhodospirillum rubrum. the potential was determined by measuring the steady-state distribution of the permeant scn- across the chromatophore membrane using a flow dialysis technique. the potential was not observed in the dark, nor in the presence of antimycin. it was dissipated on the addition of carbonyl cyanide p-trifluoromethoxyphenylhydrazone. the potential was reduced by between ...1978416847
continuous monitoring of the electrical potential across energy-transducing membranes using ion-selective electrodes. application to submitochondrial particles and chromatophores. 1978414935
homoserine dehydrogenase of rhodospirillum rubrum. physical and chemical characterization.a detailed physicochemical characterization of purified homoserine dehydrogenase of rhodospirillum rubrum is presented. the enzyme has a molecular weight of 110000 and consists of two subunits of identical molecular weight of 55000. depending on the ionic strength and protein concentration it is possible for the native enzyme to dimerize to produce an enzymatically active species of molecular weight 220000. titrations of the native and detergent-treated enzyme with a variety of sulfhydryl reagen ...1978414912
[relation of cyclic and noncyclic electron transport in rhodospirillum rubrum chromatophores. i. experimental study of the kinetic characteristics of dark reduction of p870 with different donor concentrations in the medium].the kinetics of the dark recovery of photo-oxidized bacteriochlorophyll p870 was studied as a function of the intensity and duration of actinic light illumination at different concentrations of a donor in the medium. from the comparison of the experimental data with the results of mathematical modelling of the processes under investigation [1] it is concluded that electron transport is triggered for another pathway, whenever the concentration of the donor in the medium attains a certain critical ...1978414786
a comparison of electron transport and photophosphorylation systems of rhodopseudomonas capsulata and rhodospirillum rubrum. effects of antimycin a and dibromothymoquinone.the photophosphorylation systems of rhodopseudomonas capsulata and rhodospirillum rubrum chromatophores have been compared in respect to the effects of artificial electron carriers [n-methylphenazonium methosulfate (pms) and diaminodurene], reducing agents (ascorbate in particular), and various quinones in the absence and presence of the electron transport inhibitors antimycin a and dibromothymoquinone (dbmib). in addition, the effects of both inhibitors on photosynthetic electron transport thro ...1978414685
effects of long-term treatment with acetylene on nitrogen-fixing microorganisms.long periods of experimental incubation with acetylene led to a multifold enhancement of acetylene-reducing activity in anabaena cylindrica, anabaenopsis circularis, rhodospirillum rubrum, and azotobacter vinelandii. rates of acetylene reduction showed a gradual increase and reached a peak after 2 to 6 h of continuous incubation under acetylene. thereafter, enzyme activity rapidly declined. a similar enhancement of ethylene production was observed when pretreatment with acetylene was interrupted ...1977413480
[light-induced oxygen uptake by chromatophores and subchromatophore pigment-protein complexes of rhodospirillum rubrum].chromatophores of r. rubrum incubated with electron donors, e. g. reduced diaminodurene, tmpd, phenazine methosulphate, cytochrome c or ferrocyanide, are able to catalyze o2 uptake upon illumination. this process is inhibited by o-phenanthroline as well as upon extraction of quinones from chromatophores, but not by antimycin a, rotenone or cn-. the o2 uptake sensitive to the action of o-phenanthroline is also observed in the illuminated subchromatophore p870 reaction center complexes and reactio ...1977412525
the effect of electron donors and acceptors on light-induced absorbance changes and photophosphorylation in rhodospirillum rubrum chromatophores.light-induced difference spectra between 400 and 640 nm of rhodospirillum rubrum chromatophores were performed in the presence and absence of exogenous electron donor/acceptor systems and compared with the chemical oxidation spectrum. the results indicate that the component previously defined as p430 is not a unique entity but rather represents different species, or a mixture of species, under various conditions. under all conditions in which the reaction center bacteriochlorophyll is reversibly ...1977411652
physiological studies of spirillum lipoferum. 1977411476
demonstration of two 3,3'-diaminobenzidine oxidation reactions associated with photosynthetic membranes in anaerobic light-grown rhodospirillum rubrum.photosynthetic membranes of anaerobic light-grown rhodospirillum rubrum oxidized 3,3'-diaminobenzidine. when glutaraldehyde-treated cells were exposed to 3,3'-diaminobenzidine in the light aerobically, the oxidation appeared to occur by two systems. one reaction was stimulated by white light and the second required molecular oxygen. the o2-dependent activity was inhibited by kcn.1977410873
excitation trapping by different states of photosynthetic reaction centres. 1977410664
structural aspects of the reaction center of photosynthetic bacteria calculated from triplet state zero-field splittings. 1977410658
necessity of a membrane component for nitrogenase activity in rhodospirillum rubrum.acetylene reduction catalyzed by nitrogenase from rhodospirillum rubrum has low activity and exhibits a lag phase. the activity can be increased by the addition of a chromatophore membrane component and the lag eliminated by preincubation with this component, which can be solubilized from chromatophores by treatment with nacl. it is both trypsin- and oxygen-sensitive. titration of the membrane component with nitrogenase and vice versa shows a saturation point. the membrane component interacts sp ...1977410446
isolation of an iron-molybdenum cofactor from nitrogenase.a method for the isolation of an iron-molybdenum cofactor (femoco) from component i of nitrogenase is described. this method is used to isolate femoco from aerobic, anaerobic, facultative, and photosynthetic nitrogen-fixing organisms. the fe/mo ratio in the femoco from azotobacter vinelandii and clostridium pasteurianum is 8:1. the femoco contains six atoms of acid-labile sulfide per eight fe atoms. crystalline component i from a. vinelandii contains 2 mo, 33 fe, and 27 acid-labile sulfide atoms ...1977410019
energy-linked nicotinamide nucleotide transhydrogenases. 1977409434
structure and function of carotenoids in the photoreaction center from rhodospirillum rebrum. 1977409431
isolation of the membrane-bound hydrogenase from rhodospirillum rubrum. 1977409403
isolation of a photosynthetic strain of rhodospirillum rubrum with an altered reaction center. 1977409348
[carbonic anhydrase activity of phototropic bacteria].the activity of carboanhydrase was assayed in seven species of phototrophous bacteria: three species of the rhodospirillaceae genus, three species of the chromatiaceae genus, and one species of the chlorobiaceae genus. the activity of carboanhydrase was found in five species among seven. it decreased on passing from photoautotrophous to photoheterotrophous conditions of growth, and then to dark heterotrophous conditions, which correlated with the activity of the calvin cycle in the bacteria. no ...1977408582
isolation and characterization of a bacteriochlorophyll-associated chromatophore protein from rhodospirillum rubrum g-9. 1977408189
sensitive measurement of flash induced photophosphorylation in bacterial chromatophores by firefly luciferase. 1977408188
reduction of adenylylsulfate and 3'-phosphoadenylylsulfate in phototrophic bacteria.extracts of 14 species of phototrophic bacteria, partly grown with different sulfur compounds, were tested for their ability to form volatile sulfur compounds from adenylylsulfate (aps) and 3'-phosphoadenylylsulfate (paps). the rhodospirillum species showed marked activities with both aps and paps while the rhodopseudomonas species seem to prefer paps. the chromatiaceae exhibited the strongest activities with aps, whereas chlorobium limicola had equally high activity with paps.1977408177
purification, molecular properties, and amino acid composition of the subunits of rhodospirillum rubrum succinate dehydrogenase. 1977406851
simple equipment for the growth of photosynthetic bacteria. 1977406256
a novel pathway for l-citramalate synthesis in rhodospirillum rubrum.when [14c]propionate was incubated with a cell-free extract of rhodospirillum rubrum in the presence of glyoxylate, atp, coa, mg2+, and mn2+, radioactivity was incorporated into mesaconate (msa) as well as into beta-methylmalate (mma) and citramalate (cma). msa was suggested to be an intermediate of the conversion of mma to cma based on the following observations. (i) when non-labeled msa was added to the cma-forming reaction system, radioactivity was trapped in msa. (ii) when msa was incubated ...1977405381
linear dichroism of light-induced absorbance changes of reaction centers of rhodospirillum rubrum. 1977405251
localisation of the subunits of the photosynthetic reaction centers in the chromatophore membrane of rhodospirillum rubrum.reaction centers were isolated with the detergent lauryl dimethyl amine oxide from chromatophore membranes of rhodospirillum rubrum. the subunit composition of these reaction centers is similar to the one obtained from rhodopseudomonas spheroides: three subunits with the molecular weights of 21 000, 24 000 and 29 000. reaction centers prepared from chromatophores labeled with 131i were heavely labeled in their large subunit (h). the smaller subunits (l and m) contained only little label. sonicat ...1977403945
evidence for monomeric bacteriochlorophyll in p800 of the photoreaction center from rhodospirillum find out whether weak or strong coupling exists between the bacteriochlorophyll molecules of the photoreaction center, the relative efficiency of energy transfer to p870 was measured at 795 nm and at 808 nm, at room temperature and at 77 degrees k. at room temperature, both relative efficiencies are close to 100%. however, at 77 degrees k, 795 nm light has a quantum efficiency of 76% and 808 nm light has an efficiency of 87%. these results confirm the fact that p800 is formed of at least one ...1977403944
reaction of ribulosebisphosphate carboxylase from rhodospirlilum rubrum with the potential affinity label 3-bromo-1,4-dihydroxy-2-butanone 1,4-biphosphate. 1977403917
ubiquinone and photochemical activity in rhodospirillum rubrum. 1977403533
isolation and characterization of an organic solvent soluble polypeptide component from photoreceptor complexes of rhodospirillum organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of rhodospirillum rubrum. after extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. its isoelectric point determined by isoelectric focusing was 7.10. when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified polypeptide ran as a single band of an apparent molecular weight of 12 000. however, ...1977402930
mechanisms of co2 fixation in bacterial photosynthesis studied by the carbon isotope fractionation technique.the carbon isotope discrimination properties of a representative of each of the three types of photosynthetic bacteria chlorobium thiosulfatophilum, rhodospirillum rubrum and chromatium and of the c3-alga chlamydomonas reinhardii were determined by measuring the ratio of 13co2 to 12co2 incorporated during photoautotrophic growth. 2. chromatium and r. rubrum had isotope selection properties similar to those of c3-plants, whereas chlorobium was significantly different. 3. the results suggest that ...1977402896
amino acid sequence of desulfovibrio vulgaris flavodoxin.the complete amino acid sequence for the 148-amino acid flavodoxin from desulfovibrio vulgaris was determined to be: h3n+-met-pro-lys-ala-leu-ile-val-tyr-gly-ser-thr-thr-gly-asn-thr-glu-tyr-thr-ala-glu-thr-ile-ala-arg-glu-leu-ala-asn-ala-gly-tyr-glu-val-asp-ser-arg-asp-ala-ala-ser-val-glu-ala-gly-gly-leu-phe-glu-gly-phe-asp-leu-val-leu-leu-gly-cys-ser-thr-trp-gly-asp-asp-ser-ile-glu-leu-gln-asp-asp-phe-ile-pro-leu-phe-asp-ser-leu-glu-glu-thr-gly-ala-gln-gly-arg-lys-val-ala-cys-phe-gly-cys-gly-as ...1977402366
comparison of the electrochemical proton gradient and phosphate potential maintained by rhodospirillum rubrum chromatophores in the steady state. 1977402116
comparison of glyoxalase i purified from yeast (saccharomyces cerevisiae) with the enzyme from mammalian sources.glyoxalase i from yeast (saccharomyces cerevisiae) purified by affinity chromatography on s-hexylglutathione-sepharose 6b was characterized and compared with the enzyme from rat liver, pig erythrocytes and human erythrocytes. the molecular weight of glyoxalase i from yeast was, like the enzyme from rhodospirillum rubrum and escherichia coli, significantly less (approx. 32000) than that of the enzyme from mammals (approx. 46000). the yeast enzyme is a monomer, whereas the mammalian enzymes are co ...1979393249
regulation of adenosine diphosphate glucose pyrophosphorylase. 1978345767
activation of ribulose 1,5-bisphosphate carboxylase from rhodopseudomonas sphaeroides: probable role of the small subunit.the activation properties of the form i and form ii ribulose 1,5-bisphosphate carboxylases from rhodopseudomonas sphaeroides were examined. both enzymes have a requirement of mg2+ for optimal activity. mn2+, ni2+, and co2+ can also support activity of the form i enzyme, whereas only mn2+ can substitute for mg2+ with the form ii enzyme. the effect of different preincubations on the carboxylase reaction was also examined. both enzymes exhibited a lag when preincubated with other than mg2+ and co2 ...1979316430
homoserine dehydrogenase: spontaneous reactivation by dissociation of p-mercuribenzoate from an inactive enzyme--p-mercuribenzoate complex.incubation of rhodospirillum rubrum homoserine dehydrogenase (l-homoserine:nad+ oxidoreductase, ec with p-mercuribenzoate (pmb) in the presence of 0.2 m kcl and 2 mm l-threonine resulted in complete loss of enzyme activity. upon removal of excess pmb, kcl, and l-threonine, a time-dependent recovery of enzyme activity was observed in 25 mm phosphate/i mm edta buffer, ph 7.5. circular dichroism studies indicated that the transition from inactive to reactivated form of the enzyme was accom ...1977270718
[role of ferredoxin in the metabolism of hydrogen by rhodospirillum rubrum].ferredoxin was purified after isolation from the cells of rhodospirillum rubrum grown under photoheterotrophic conditions; a385/a280 in the absorption spectrum was not less than 0.53; the molecular weight was ca. 7700; e0' (ph 7.0)--430 mv. ferredoxin was easily reduced in the presence of dithionite and provided a high rate of nadp reduction by pea chloroplasts. the extracts of r. rubrum containing ferredoxin or the extracts, to which it was added, reduced nad in the presence of hydrogen and evo ...1975241001
the reaction of rhodospirillum rubrum cytochrome c2 with iron hexacyanides.the reaction of rhodospirillum rubrum cytochrome c2 with the nonphysiological reactants, ferrocyanide and ferricyanide has been investigated as a function of ionic strength, temperature and ph, using both stopped-flow and temperature-jump kinetic methods. the results are consistent with a complex reaction mechanism involving the formation of two intermediate complexes. the site of electron transfer appears to be at the front of the cytochrome c2 molecule near the hem e crevice with interacton of ...1975238661
postillumination adenosine triphosphate synthesis in rhodospirillum rubrum chromatophores. i. conditions for maximal yields.the very low level of postillumination atp synthesis in chromatophores was markedly stimulated when permeant anions (thiocyanate or perchlorate) or permeant cations (potassium in the presence of valinomycin) were added to the light stage. although these compounds stimulated also light-induced proton uptake in chromatophores the ph dependence of both photoreactions was different. proton uptake peaked at ph 6.5 while the amount of postillumination atp was maximal when the light stage was carried o ...1975237896
characterization of the phototrap in photosynthetic bacteria. 1975237454
a study on the membrane potential and ph gradient in chromatophores and intact cells of photosynthetic bacteria.generation of membrane potential (delta psi) and transmembrane ph difference (delta ph) was studied in ppi-energized chromatophores of rhodospirillum rubrum by means of measurements of carotenoid and bacteriochlorophyll absorption changes, atebrin and 8-anilinonaphthalene-1-sulphonate fluorescence responses, and phenyldicarbaundecaborane transport. the data obtained are consistent with the suggestion that carotenoid, bacteriochlorophyll and phenyldicarbaundecaborane responses are indicators of ...1975236031
resolution and reconstitution of rhodospirillum rubrum pyridine dinucleotide transhydrogenase. proteolytic and thermal inactivation of the membrane component.pyridine dinucleotide transhydrogenase of the rhodospirillum rubrum chromatophore membrane was readily resolved by a washing procedure into two inactive components, a soluble transhydrogenase factor protein and an insoluble membrane-bound factor. transhydrogenation was reconstituted on reassociation of these components. the capacity of the membrane factor to reconstitute enzymatic activity was lost after proteolysis of soluble transhydrogenase factor-depleted membranes with trypsin. nadp+ or nad ...1975234441
photosynthetic and respiratory electron flow in the dual functional membrane of facultative photosynthetic bacteria. 1978233518
[reconstitution of electrogenic function of pyrophosphatase isolated from rhodospirillum rubrum membranes].the membrane vesicles (proteoliposomes) have been reconstituted from phospholipids and inorganic pyrophosphatase (ec isolated from rhodospirillum rubrum chromatophores. an addition of inorganic pyrophosphate (ppi) causes a mg2+-dependent formation of a transmembrane electric potential difference and an uptake of penetrating tetraphenylborate anions by the proteoliposomes. thus, isolated pyrophosphatase, being incorporated into the phospholipid membrane, functions as a mgppi-dependent pr ...1979232668
characterization of the membrane-bound inorganic pyrophosphatase in rhodospirillum rubrum.the membrane-bound inorganic pyrophosphatase (ec from rhodospirillum rubrum has been investigated with the tools of enzyme kinetics, and with two amino acid reagents, n-ethyl-maleimide (malnet) and 4-chloro-7-nitrobenzofurazan (nbf-cl). 1. the concentration of the true substrate, mgppi, was varied with constant concentrations of free mg2+ or ppi. it was observed that mg2+ acted as an activator. 2. heat inactivation of the enzyme at 62 degrees c was slowed down in the presence of mg2+. 3 ...1979230038
transfer of light-induced electron-spin polarization from the intermediary acceptor to the prereduced primary acceptor in the reaction center of photosynthetic reaction centers and chromatophores of photosynthetic bacteria strong light-induced emissive esr signals have been found, not only after a flash but also under continuous illumination. the signal, with g = 2.0048 and delta hpp = 7.6 g, is only present under reducing conditions in material in which the primary acceptor, ubiquinone, u and its associated high-spin ferrous ion are magnetically uncoupled. its amplitude under continuous illumination is strongly dependent on light intensity and on m ...1979228714
orientation of the bacteriochlorophyll triplet and the primary ubiquinone acceptor of rhodospirillum rubrum in membrane multilayers determined by esr spectroscopy (i).chromatophores from rhodospirillum rubrum were oriented as multilayers on quartz slides under reducing conditions. irradiation of these multilayers in the resonance cavity of an esr spectrometer at 6 k yielded the spectrum of the bacteriochlorophyll dimer triplet. the relative intesities of the main six lines of the triplet were dependent on the angle subtended by the direction of the external magnetic field with plane of the multilayers. the angular dependence of the intensities of these transi ...1979228709
iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. electron paramagnetic resonance of the carbon monoxide inhibited state.carbon monoxide inhibits reduction of dinitrogen (n2) by purified nitrogenase from azotobacter vinelandii and clostridium pasteurianum in a noncompetitive manner (kii and kis = 1.4 x 10(-4) and 4.5 x 10(-4) and 7 x 10(-4) atm and 14 x 10(-4) atm for the two enzymes, respectively). the onset of inhibition is within the turnover time of the enzyme, and co does not affect the electron flux to the h2-evolving site. the kinetics of co inhibition of n2 reduction are simple, but co inhibition of acetyl ...1979228701
[possible pathways for acetyl-coa formation by purple bacteria].purple sulfur (ectothiorhodospira shaposhnikovii, chromatium minutissimum, lamprobacter modestohalophilus, thiocapsa roseopersicina) and nonsulfur (rhodospirillum rubrum, rhodopseudomonas palustris, rhodopseudomonas spheroides) bacteria are capable of forming acetyl-coa synthetase, phosphotransacetylase and acetokinase independent of the medium composition and growth conditions. in all of the purple sulfur bacteria with an exception of e. shaposhnikovii, the activity of acetokinase is much highe ...1979228168
[free radical centers in the chromatophores and preparations of rhodospirillum rubrum reaction centers].the light-induced free radical esr signals in chromatophores and reaction center preparation of r. rubrum were studied. it has been shown that the properties of the signals in both systems were strictly identical. at the microwave powers higher than 10 mw the esr signal at g approximatley 2.00 is saturated and its asymmetry arises. changes of the esr signal shape may be explained by the superposition of p870+ signal with that from the ubisemiquinone. addition of ferricyanide to chromatophores in ...1979224953
properties of the solubilized membrane-bound hydrogenase from the photosynthetic bacterium rhodospirillum rubrum. 1979224815
the chronoamperometric determination of homogeneous small molecule-redox protein reaction rates. 1979224724
regulation of cyclic photophosphorylation in rhodospirillum rubrum by the redox state of nicotinamide-adenine dinucleotide.we have investigated the effect of the redox state of added nad on the rates of anaerobic cyclic photophosphorylation which are supported by membrane vesicles isolated from rhodospirillum rubrum. as the redox potential of nad was lowered, the activity decreased according to a typical potentiometric titration. the nernst plot showed an apparent midpoint potential (e'o) of -350 mv and had a slope which corresponded to a two-electron transition. besides, an almost identical potentiometric relations ...1979223636
structure and function of photoreaction-centre chlorophyll.evidence from electron paramagnetic resonance (e.p.r.) studies suggests that the unpaired spin in oxidized p700+. or p865+. is shared by two special chlorophyll a (chl a) or bacteriochlorophyll a (bchl a) molecules respectively. three classes of models have been proposed for special pair reaction centre chlorophyll: asymmetric, in which one chl a (or bchl a) acts as electron donor to a second acting as acceptor; models with translational symmetry only; and models with c2 symmetry. models with c2 ...1978222557
anomalies in amino acid sequences of small cytochromes c and cytochromes c' from two species of purple photosynthetic bacteria. 1979221823
[determination of the distance between charges following their photoseparation in chromatophores from r. rubrum]. 1979221054
the amino acid sequence of cytochrome c' from the purple sulphur bacterium chromatium amino acid sequence is proposed for the cytochrome c' from the photosynthetic purple sulphur bacterium chromatium vinosum strain d. it is single polypeptide chain of 131 residues, with haem-attachment cysteine residues at positions 121 and 124. the results discredit an earlier report [dus, bartsch & kamen (1962) j. biol. chem 237, 3083--3093] of a di-haem peptide sequence from this protein. the sequence belongs to the same class as the published alcaligenes and rhodospirillum rubrum cytochrom ...1979220951
comparative solvent perturbation of horse heart cytochrome c and rhodospirillum rubrum cytochrome c2.the extent of exposure of heme to solvent in horse heart cytochrome c and rhodospirillum rubrum c2 was investigated to determine whether a correlation exists between the properties of these oxidation-reduction proteins and their heme environments. solvent perturbation absorption difference spectra were measured using ethylene glycol, glycerol, and sucrose at concentrations between 0 and 30%. cytochrome c appears to exhibit a somewhat greater extent of heme exposure than cytochrome c2 for both th ...1979220233
isolation and characterization of a membrane-bound, low-potential c-type cytochrome from purple photosynthetic bacteria, with special reference to rhodospirillum rubrum.other investigators have isolated soluble, low-potential, c-type cytochromes (cytochrome c3) from a few photosynthetic procaryotes, i.e., a cyanobacterium and two species of purple nonsulfur bacteria. however, such cytochromes appeared to be absent from other purple bacteria, including rhodospirillum rubrum and chromatium vinosum. we now report evidence for the presence of low-potential c-type cytochromes in these two species, in which they were found to be bound to the photosynthetic membranes. ...1978214418
distribution of adenosine 5'-triphosphate (atp)-dependent hexose kinases in microorganisms.a systematic study of adenosine triphosphate (atp)-dependent hexose kinases among microorganisms has been undertaken. sixteen hexose kinases of five major types were partially purified from 12 microorganisms and characterized with respect to specificity for sugar and nucleotide substrates and michaelis constants for the sugar substrates. glucokinase activities that phosphorylate glucose and glucosamine are inhibited by n-acetyl-glucosamine and xylose, were found to be present in the non-sulphur ...1978214181
flash-induced photophosphorylation in rhodospirillum rubrum chromatophores. i. the relationship between cytochrome c-420 content and photophosphorylation.the content of cytochrome c-420 in rhodospirillum rubrum chromatophores prepared by grinding with alumina is 5--10% of that in whole cells, and 20--40% in chromatophores by 'french' pressing. flash-induced phosphorylation of various chromatophores which varied in cytochrome content from 7 to 40% is proportional to the cytochrome content. extrapolating the cytochrome c-420 content to that observed in whole cells, a ratio atp/p+x- near 1 is calculated. at low flash intensity the phosphorylation pe ...1978213110
on the significance of electron transport systems for growth of rhodospirillum rubrum. 1978211972
relationships in hydrogen metabolism between hydrogenase and nitrogenase in phototrophic bacteria.purple bacteria rhodospirillum rubrum and thiocapsa roseopersicina form two enzymes, hydrogenase and nitrogenase, which participate in hydrogen metabolism. h2 photoproduction in these bacteria is associated mainly or completely with the action of nitrogenase. the soluble and membrane-bound hydrogenases of t. roseopersicina have similar physicochemical properties (mol. weight, subunit composition, n-terminal amino acids, fe2+ and s2- content, pl. eo'). in comparison with other hydrogenases the en ...1978208659
mössbauer study of cytochrome c2 from rhodospirillum rubrum. sign of the product gxgygz of some low spin ferric heme proteins.we have studied cytochrome c2 from rhodospirllum rubrum with mössbauer spectroscopy and electron paramagnetic resonance. the mössbauer data on the ferric protein, taken in external magnetic fields up to 50 kg, were analyzed within the framework of the ligand field model commonly used to evaluate low-spin ferric heme compounds. the data analysis shows that the determinant of the electronic g-tensor, i.e. the product gxgygz, is positive for cytochrome c2. we have reanalyzed published mössbauer dat ...1978208633
electron spin resonance in zero magnetic field of the reaction center triplet of photosynthetic bacteria.the decay rates kx, ky, kz of the individual spin levels of the light-induced triplet state have been accurately measured by the zero-field resonance technique under conditions of very low light intensity and a microwave sweep rate of 2.5 mhz/microseconds, which is in excess of that commonly used in optical detection magnetic resonance experiments. the rates ku found correspond well with those previously determined under somewhat different conditions (hoff, a.j. (1976) biochim. biophys. acta 440 ...1978208604
phenazine methosulfate mediated photoinactivation of some energy linked reactions in rhodospirillum rubrum. 1978208532
reduction of nicotinamide adenine dinucleotide by pyruvate:lipoate oxidoreductase in anaerobic, dark-grown rhodospirillum rubrum mutant c.cell extracts from fermentatively grown rhodospirillum rubrum reduced about 80 nmol of nicotinamide adenine dinucleotide (nad) per mg of protein per min under anaerobic conditions with sodium pyruvate. the reaction was specific for pyruvate and nad; nad phosphate was not reduced. results indicated that pyruvate-linked nad reduction occurred via pyruvate:lipoate oxidoreductase. the reaction required catalytic amounts of both coenzyme a and thiamine pyrophosphate. addition of sodium arsenite inhib ...1978207677
adenylate kinase from rhodospirillum rubrum.a partial purification and some properties of adenylate kinase from the photosynthetic bacterium rhodospirillum rubrum are described.1978207554
[effect of growth conditions on the activity of the enzymes of cyclic 3':5'-amp synthesis and decay in phototrophic bacteria].activity, ratio and summary content of cyclic amp enzymes, adenylate cyclase and phosphodiesterase varied depending on growth conditions of phototrophic bacteria (rhodospirillum rubrum and rhodopseudomonas palustris). it suggests, that membrane-bound and soluble enzymes carry different functions. the increase of adenylate cyclase under chaning growth conditions was usually accompanied by the increase of phosphodiesterase. sharp increase of both enzymes activity was observed when bacteria were gr ...1978207363
preliminary crystallographic data for cytochromes c' of rhodopseudomonas capsulata and rhodospirillum molischianum. 1977204789
electron spin polarization in photosynthesis and the mechanism of electron transfer in photosystem i. experimental observations.transient electron paramagnetic resonance (epr) methods are used to examine the spin populations of the light-induced radicals produced in spinach chloroplasts, photosystem i particles, and chlorella pyrenoidosa. we observe both emission and enhanced absorption within the hyperfine structure of the epr spectrum of p700+, the photooxidized reaction-center chlorophyll radical (signal i). by using flow gradients or magnetic fields to orient the chloroplasts in the zeeman field, we are able to influ ...1978204369
facile assay of enzymes unique to the calvin cycle in intact cells, with special reference to ribulose 1,5-bisphosphate carboxylase. 1978204219
comparative kinetic-ionic strength study of two differently charged cytochrome c: effects are limited to overall charge. 1977202274
reduction kinetics of bacterial cytochromes c2. 1977202201
a novel electron paramagnetic resonance signal associated with the 'primary' electron acceptor in isolated photochemical reaction centers of rhodospirillum rubrum. 1977200472
isolation and characterization of bound ion-sulfur proteins from bacterial photosynthetic membranes. ii. succinate dehydrogenase from rhodospirillum rubrum chromatophores. 1977199588
isolation and characterization of bound ion-sulfur proteins from bacterial photosynthetic membranes. i. ferredoxins iii and iv from rhodospirillum rubrum chromatophores. 1977199587
mössbauer studies of cytochrome c' from rhodospirillum rubrum.cytochrome c' from rhodospirillum rubrum has been investigated in the ferric form with mössbauer and epr spectroscopy. in the ph range from 6 to 9.5, three species are observed which belong to two ph-dependent equilibria with pk values near 6 and 8.5. the pk = 6 transition is resolved only with high-field mössbauer spectroscopy. for the three species we have determined the zero-field splitting parameters and the hyperfine coupling constants. the data were fitted to a spin hamiltonian which takes ...1977199273
structure and function of cytochromes c. 1977197877
Displaying items 2001 - 2100 of 2252