Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
interaction of ribulose bisphosphate carboxylase/oxygenase with 2-carboxyhexitol 1,6-bisphosphates.2-c-carboxy-d-glucitol 1,6-bisphosphate (cgbp) and 2-c-carboxy-d-mannitol 1,6-bisphosphate (cmbp) have been synthesized, isolated, and the structures of these compounds and the derived lactones elucidated by nmr spectroscopy and periodate oxidation. both carboxyhexitol bisphosphates, which are homologs of the transition state analog 2-c-carboxy-d-arabinitol 1,5-bisphosphate, exhibit competitive inhibiton of ribulose bisphosphate carboxylase/oxygenase (ec 4.1.1.9) isolated from spinach (spinacia ...19836573158
nitrogen fixation and nitrogenase activities in members of the family rhodospirillaceae.strains of all 18 species of the family rhodospirillaceae (nonsulfur photosynthetic bacteria) were studied for their comparative nitrogen-fixing abilities. all species, with the exception of rhodocyclus purpureus, were capable of growth with n2 as the sole nitrogen source under photosynthetic (anaerobic) conditions. most rapid growth on n2 was observed in strains of rhodopseudomonas capsulata. within the genus rhodopseudomonas, the species r. capsulata, r. sphaeroides, r. viridis, r. gelatinosa, ...19846581158
species variation in kinetic properties of ribulose 1,5-bisphosphate carboxylase/oxygenase.several kinetic parameters of ribulose-1,5-bisphosphate (rubp) carboxylase/oxygenase from different species were measured and compared. the co2/o2 specificity (vcko/vokc) was found to be about 80 in the enzymes from several c3 species and two c4 species. specificity values of 58 and 70, respectively, were found in enzymes from the c4 plants setaria italica and sorghum bicolor. two enzymes from cyanobacteria had values of about 50. substitution of mn2+ for mg2+ reduced the co2/o2 specificity by a ...19836582802
[generic interrelations of purple bacteria in the genus rhodopseudomonas].the technique of dna--dna hybridization was used to study relations offween purple nonsulfur bacteria (the family rhodospirillaceae). the level of homologies with rhodopseudomonas sphaeroides 8259 was nearly the same for different species (8-17%) in the genus rhodopseudomonas under the conditions optimal for hybridization. the same level of homologies was found for the dna of rhodospirillum rubrum, a species belonging to another genus of purple nonsulfur bacteria (13%). rhodomicrobium vannielli ...19846610816
o-acetylserine sulfhydrylase and s-sulfocysteine synthase activities of rhodospirillum tenue.o-acetylserine sulfhydrylase in cell-free extracts of rhodospirillum tenue was markedly repressed after growth in the presence of sulfide or thiosulfate, whereas s-sulfocysteine synthase activity remained almost unchanged. purification on de52 cellulose resulted in the separation of two proteins: protein i with a molecular weight of 57000 had o-acetylserine sulfhydrylase activity only, while protein ii with a molecular weight of 46000 had s-sulfocysteine synthase activity in addition. the activi ...19836615127
the effects of light and oxygen on membrane assembly in the photosynthetic bacteria. 19836617969
molecular properties of fumarate reductase isolated from the cytoplasmic membrane of escherichia coli.fumarate reductase, purified from the cytoplasmic membrane of escherichia coli, has been cross-linked with the bifunctional reagent dimethylsuberimidate and shown to exist as an alpha beta dimer of polypeptides of molecular weights 69,000 and 25,000 in a 1:1 molar ratio. the protein has an s20,w of 7.67s and a d20,w of 6.5 x 10(-7) cm2/s. the purified enzyme contained 4-5 mol of nonheme iron and 4-5 mol of acid labile sulfur while the visible absorption spectrum showed a broad peak between 400 a ...19826751504
activationless electron transfer processes in biological systems. 19806766403
polyadenylated messenger rnas code for photo reaction center and light-harvesting antenna polypeptides of rhodospirillum rubrum. 19806766405
purification and properties of polynucleotide phosphorylase from photosynthetic bacterium rhodospirillum rubrum.1. polynucleotide phosphorylase [polyribonucleotide: orthophosphate nucleotidyltransferase, ec 2.7.7.8] was purified to near homogeneity from the photosynthetic bacterium, rhodospirillum rubrum. the purified enzyme had a molecular weight of approximately 160,000, and consisted of two equivalent subunits of approximately 76,000 daltons. it catalyzed the three reactions described below. 2. in the exchange reaction of the beta-phosphate of nucleoside diphosphates with pi by the purified enzyme in t ...19806766923
short-lived delayed luminescence of photosynthesizing organisms. ii. the ratio between delayed and prompt fluorescence as studied by the modulation method.the ratio between the intensities of delayed and prompt fluorescence was studied for different photosynthetic objects under different conditions by modulation method. the method is based on excitation of luminescing objects by light, modulated harmonically, and on a combined study of phase shifts and demodulation coefficients of the luminescence as related to excitation light. the presence of intense delayed emissions was revealed in purple bacteria, ectothiorhodospira shaposhinokovii, rhodospir ...19806768385
photo-induced electron transport and water state in rhodospirillum rubrum chromatophores.it is shown that in bacterial chromatophores the pronounced changes in the free water content with a proton spin-spin relaxation time (t2) of 10(-3)--10(-2) s does not influence the efficiency of electron transfer from the photosynthetic reaction centre to the membrane pool of secondary acceptors. an abrupt inhibition of this process occurs only after the loss of the water with faster proton spin-spin relaxation time (t2 of 10(-4) s). the process is reversible. the water fraction in question is ...19806768386
detection of cytochrome b+50 in membranes of rhodospirillum rubrum isolated from aerobically and phototrophically grown cells.1. dark equilibrium potentiometric titrations were conducted on membranes purified from rhodospirillum rubrum in an effort to identify b-type cytochrome components reported in other rhodospirillaceae. in preparations from aerobically grown cells virtually devoid of bacteriochlorophyll a, three components were observed at 560-540 nm. their oxidation-reduction midpoint potentials assigned by computer-assisted analysis were +195, +50 and -110 mv at ph 7.0; each of these fitted closely to theoretica ...19806769433
formation of intracytoplasmic membranes in chemotrophic mecillinam sphaeroplasts of rhodospirillum rubrum.chemotrophically growing cells of rhodospirillum rubrum were transformed into sphaeroplasts of irregular shape under the influence of the penicillin antibiotic mecillinam. on a cell protein basis, respiratory activities of whole sphaeroplasts were slightly decreased as compared with the untreated control. but, on a membrane protein basis various activities of the respiratory chain were largely identical in membrane preparations from untreated cells and sphaeroplasts, respectively. chemotrophical ...19806769673
the dependency of proton extrusion in the light on the developmental stage of the photosynthetic apparatus in rhodospirillum rubrum.the rate of proton extrusion by whole cells of rhodospirillum rubrum is constant on a bacteriochlorophyll basis only above cellular bacteriochlorophyll concentrations of about 10 nmol bacteriochlorophyll per mg cell protein. at specific bacteriochlorophyll cellular levels below this value, the rate of proton extrusion per bacteriochlorophyll increases. correspondingly, membrane preparations isolated from these cells exhibit increases in the rate of proton uptake on a pigment basis. concomitant w ...19806770898
energy transfer and bacteriochlorophyll fluorescence in purple bacteria at low temperature.emission spectra of bacteriochlorophyll a fluorescence and absorption spectra of various purple bacteria were measured at temperatures between 295 and 4 k. for rhodospirillum rubrum the relative yield of photochemistry was measured in the same temperature region. in agreement with earlier results, sharpening and shifts of absorption bands were observed upon cooling to 77 k. below 77 k further sharpening occurred. in all species an absorption band was observed at 751-757 nm. the position of this ...19806772218
[photoinduced changes in dielectric losses in the microwave region in rhodospirillum rubrum photosynthesizing bacteria]. 19806772239
[photoinduced changes in dielectric losses in the microwave region in chromatophores of rhodospirillum rubrum photosynthesizing bacteria]. 19806772240
[linear dichroism of pigments associated with spherical chromatophores. models of orientation in polyacrylamide gels].linear dichroism and orientation of pigments in chromatophores of photosynthetic bacteria chromatium minutissimum and rhodospirillum rubrum using a novel method of orientation in polyacrylamide gel was studied. a model is proposed for orientation of spherical membranes of chromatophores or other similar vesicules. the value of linear dichroism is derived for known deformation of the gel and a certain angle between the transition dipole and a unit vector perpendicular to the membrane plane. the a ...19806772937
carotenoid triplet yields in normal and deuterated rhodospirillum rubrum.quantum yields of carotenoid triplet formation in rhodospirillum rubrum wild type and fully deuterated cells and chromatophores were determined in weak laser flashes for excitation wavelength lambda i = 530 nm (mainly absorbed by the carotenoid spirilloxanthin) and for lambda i = 608 nm (mainly absorbed by bacteriochlorophyll) in the presence and absence of magnetic fields. all experiments were performed at room temperature and in the absence of oxygen. the quantum yield of reaction center bacte ...19806773564
evidence for a correlation between the photoinduced electron transfer and dynamic properties of the chromatophore membranes from rhodospirillum rubrum. 19806773810
effect of l-methionine-dl-sulphoximine on the photoproduction of hydrogen by rhodospirillum rubrum.the repression of photoproduction of hydrogen by ammonia could be relieved by l-methionine-dl-sulfoximine. in the absence of ammonia, hydrogen evolution was inhibited by concentrations of l-methionine-dl-sulfoximine higher than 0.1 mm.19806774882
isolation and sequence of the pyridoxal 5'-phosphate active-site peptide from rhodospirillum rubrum ribulose-1,5-bisphosphate carboxylase/oxygenase.ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum was modified with pyridoxal 5'-phosphate and then reduced with sodium borohydride. both carboxylase and oxygenase activities were lost when one molecule of pyridoxal 5'-phosphate was bound per enzyme dimer. peptide maps of modified enzyme showed one n6-(phosphopyridoxal)lysine-containing peptide. this peptide was isolated by gel filtration and cation-exchange chromatography and its sequence determined as ala-leu-gly-arg-p ...19806775695
the photoreaction center of rhodospirillum rubrum mutant strain f24.1.rhodospirillum rubrum strain f24.1 is a spontaneous revertant of nonphototrophic mutant f24 derived from wild-type strain s1. strain f24 shows no detectable photochemical activity and contains, at most, traces of the photoreaction center polypeptides. strain f24.1 has a phototrophic growth rate close to that of the wild-type strain (picorel, r., del valle-tascón, s. and ramírez, j.m. (1977) arch. biophys. biochem. 181, 665-670) but shows little photochemical activity. light-induced absorbance ch ...19806775699
differences in the architecture of cytoplasmic and intracytoplasmic membranes of three chemotrophically and phototrophically grown species of the rhodospirillaceae.freeze-fracture faces of membranes of either chemotrophically or phototrophically grown rhodospirillum rubrum, rhodopseudomonas sphaeroides, and rhodospirillum tenue were analyzed. all three species differed from each other with respect to size as well as numerical density (number per square micrometer) of intramembrane particles. in r. rubrum the number of particles on exoplasmic fracture faces of the cytoplasmic membrane stayed nearly constant (about 900 particles per microns2), but on the pla ...19806776096
polarographic measurement of h2 in aqueous solutions. 19806776845
[thiosulfate oxidation by nonsulfur purple bacteria].the capability to oxidize thiosulfate was studied in 11 cultures of purple bacteria belonging to rhodomicrobium vannielii, rhodopseudmonas viridis, rh. sphaeroides, rh. capsulata, and rhodospirillum rubrum. all the bacteria oxidized thiosulfate under aerobic conditions in the dark. the strains 2r, 8259, a1, a2 and d1 of rh. sphaeroides oxidized thiosulfate under anaerobic conditions in the light, and the process was coupled with carbon dioxide fixation. all the strains contained thiosulfate redu ...19806777642
[conformational mobility and theory of the mössbauer effect in biological systems. (model of a brownian oscillator strongly damped for conformational modes)].specific features of the mössbauer effect on proteins are discussed. it is found that the temperature dependence of recoilless gammaquantum absorption, f'(t), cannot be explained in terms of solid effects or diffusion spectrum broadening in liquids. a sharp decrease in f'(t) at temperature above 200 degrees k that has been found is due to the specificity of the conformational mobility of proteins and due to a smaller correlation time for spacially-confined diffusion of a mössbauer label tracer b ...19806777658
inhibition of nitrogenase activity by nh+4 in rhodospirillum rubrum.nitrogenase activities and the patterns of in vivo inhibition of nitrogenase by nh+4 were compared in rhodospirillum rubrum grown under several conditions of nitrogen availability. in cells grown on n2 or glutamate plus n2, nitrogenase activity was relatively low and was totally inhibited by added nh+4 in 15 to 20 min. in contrast, cells grown on glutamate alone displayed higher nitrogenase activity, and nh+4 had very little effect. cells grown on limiting amounts of nh+4 had lower nitrogenase a ...19816780531
the inhibition of photosynthetic electron transfer in rhodospirillum rubrum by n ,n' -dicyclohexylcarbodiimide.n ,n' -dicyclohexylcarbodiimide (dccd) at concentrations above 0.1 mm inhibits light-induced generation of a membrane potential in the course of cyclic and non-cyclic electron transfer, as well as light-induced oxygen uptake due to interaction of photoreduced secondary (loosely bound) ubiquinone with o2 in rhodospirillum rubrum chromatophores. similarly to o-phenanthroline, dccd blocks the electron transfer in the chromatophores between the primary (tightly bound) and secondary ubiquinones.19816781540
[cyclic electron transfer and membrane potential generation in chromatophores on non-sulfur bacteria rhodospirillum rubrum].the uptake of permeant anions by cells and chromatophores of the non-sulfur purple bacteria r. rubrum has been studied. antimycin a causes biphasic inhibition of the light-induced uptake of tetraphenylborate anions (tb-) by the cells and the isolated chromatophores incubated under anaerobic conditions. the first phase is observed at small concentrations of antimycin and is due to its effect as an inhibitor of the cyclic electron transfer. the second phase is observed at concentrations higher tha ...19806783130
x-ray diffraction studies on chromatophore membrane from photosynthetic bacteria. i. diffraction pattern of the photoreaction unit isolated from rhodospirillum rubrum chromatophore and some characteristics of the structure.the x-ray diffraction pattern from chromatophore membranes of a photosynthetic bacterium, rhodospirillum rubrum, indicates that a highly organized protein assembly exists in the membrane. the x-ray scatterer was solubilized from chromatophores by a mixture of cholate and deoxycholate. the basic component was identified as the photoreaction unit, which consists of light-harvesting bacteriochlorophyll proteins and a reaction center. the radial autocorrelation function, calculated directly from the ...19816783640
a low-angle laser light scattering study of the association behavior of a major membrane protein of rhodospirillum rubrum chromatophore at various concentrations of sodium dodecyl sulfate where polypeptides derived from water-soluble globular proteins are solubilized monomerically.the major membrane protein of rhodospirillum rubrum chromatophore could be solubilized in the presence of free sodium dodecyl sulfate (sds) in concentration above 0.8 mm. at this concentration, the protein was highly associated to give a weight-averaged molecular weight as high as one million as determined by the low-angle laser light scattering technique. with the increase of free sds concentration, the aggregates were progressively dissociated to give a molecular weight of 8300 at the critical ...19816784770
[charge transfer in the primary processes of photosynthesis].transmission of electric charges generated by light in the unbranching chain of electron transport is under consideration. recombination of electrons and holes and possibility of reverse processes are considered. expression for the efficiency of steady-state charge separation is obtained. example of the reaction centre of bacterial photosynthesis is considered. all this permits to connect the signals of microwave photolosses with the destination of the electron on distant electron carriers.19816784776
[study of microwave photolosses in chromatophores of photosynthesizing rhodospirillum rubrum bacteria].the study of photoinduced dielectric losses at frequency 10(10) c/s as function of samples humidity, heating and chemical treatment, intensity and wavelength of light is reported. the signals of microwave losses and differential spectrum signals are compared. the authors attribute the photolosses observed to the electrons localised in the realm between the primary and secondary acceptors during their reduction, probably being in the conductance quasiband of proteins in the photosynthetic reactio ...19816784778
control of 5-aminolevulinic acid synthetase activity in phototrophic facultative bacteria. purification and some properties of the enzyme from rhodospirillum rubrum. 19816786365
[structural organization of membranes reconstituted from phospholipids and subchromatophore pigment-protein complexes].pigment--protein complexes of the p870 reaction centers and complexes of the bacteriochlorophyll light-harvesting antenna were isolated from the chromatophores of the non-sulfur purple bacterium rhodospirillum rubrum by solubilization with detergents. the proteoliposomes containing the reaction centers or reaction centers and the light-harvesting antenna as well as liposomes formed from phospholipids were obtained by a self-assembly procedure using seya bean phospholipids. the freeze-fracture st ...19806786374
[kinetics of ubisemiquinone redox changes in primary reactions of bacterial photosynthesis].absorbance changes at 450 nm of the semiquinone form of the secondary electron acceptor were studied in chromatophores of rhodospirillum rubrum. when chromatophores are illuminated by a series of single turnover flashes ubisemiquinone is formed and destroyed on alternate flashes at ambient redox potential from 100 to 250 mv. a simple kinetic model of the binary oscillations is suggested. on the base of the model it is shown that the rate constant of electron transfer from primary to secondary qu ...19816789145
[kinetics of the generation of a photo-induced electric potential in chromatophores of photosynthetizing bacteria].flash-induced formation of an electric potential difference (delta psi) was monitored by a direct method in chromatophores associated with the collodion phospholipid membrane. in rhodospirillum rubrum and rhodopseudomonas sphaeriodes chromatophores, the kinetics of delta psi generation exhibit fast (tau less than or equal to 0.3 microseconds) and slow (tau congruent to 200 microseconds) phases, the latter observed in the presence of exogenous quinones. comparison of the kinetic and potentiometri ...19816789146
sequences of tryptic peptides containing five cysteinyl residues of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. 19816789776
[photooxidation and light-induced transport of phenazine methosulfate in chromatophores of purple bacteria].the light-induced interaction of phenazine methosulfate (pms) with chromatophores of the purple bacteria rhodospirillum rubrum and rhodopseudomonas sphaeroides was studied, using an ion-specific electrode. illumination caused an initial rapid increase in the concentration of methylphenazinium cation (mp+) and a subsequent slow (1-3 min) decrease of the mp+ concentration to a low steady level. the rapid phase of the light-induced mp+ concentration change is specifically enhanced by ascorbate. the ...19816789897
effect of oxygen on acetylene reduction by photosynthetic bacteria.the effect of dissolved oxygen concentration on nitrogenase activity was studied in three species of photosynthetic bacteria. the o2 concentration in the cell suspension was measured with an o2 electrode inserted into the reaction vessel. acetylene reduction by whole cells of rhodopseudomonas capsulata, rhodospirillum rubrum, and chromatium vinosum strain d was inhibited 50% by 0.73, 0.32, and 0.26 microm o2, respectively. the inhibition of the activity by o2 in r. capsulata usually was reversed ...19816790517
[role of cofactors in membrane potential generation by rhodospirillum rubrum chromatophores incorporated in a teflon filter].the chromatophores of the bacterium rhodospirillum rubrum were incorporated into a teflon filter impregnated with a decane solution of phospholipids and the light-induced electric potential difference (delta psi) between the aqueous phases separated by the filter was measured. the generation of delta psi in such a system at continuous light requires the presence of cofactors, i. e. artificial electron donors and acceptors. these cofactors provide for a steady-state flow of e by regenerating the ...19816791704
steady-state measurements of delta ph and delta psi in rhodospirillum rubrum chromatophores by two different methods. comparison with phosphorylation potential.the ph gradient, delta ph, and the membrane potential, delta psi, formed during light-induced electron transport in rhodospirillum rubrum chromatophores were measured by two independent methods: (a) using specific electrodes to monitor light-dependent uptake of nh4cl and scn- at chromatophore concentrations of about 0.1 mg bacteriochlorophyll/ml and (b) using 9-aminoacridine and 8-anilinonaphthalenesulfonic acid as fluorescent probes for delta ph and delta psi, respectively, at chromatophore con ...19816793067
fast stages of photoelectric processes in biological membranes. iii. bacterial photosynthetic redox system.chromatophores of photosynthetic bacteria rhodospirillum rubrum, rhodopseudomonas sphaeroides and chromatium minutissimum were associated with a collodion film impregnated with a decane solution of asolectin. a very short light flash inducing a single turnover of the chromatophore photosynthetic redox system was found to induce the formation of an electrical potential difference amounting to 60 mv, directed across the film as measured with an orthodox electrometer technique. the main phase of th ...19816793358
ferredoxin excreted from photosynthetic bacterium, rhodospirillum rubrum: purification and properties.when the photoheterotroph, rhodospirillum rubrum, was grown in the light, ferredoxin was excreted from the cells in a significant amount, as well as hydrogenase. the extracellular ferredoxin was purified to a homogeneous state. the molecular weight was approximately 9,000, and the oxidation-reduction mid-potential was -0.29 v (n=1) at ph 7.0 and 25 degrees c. the amino acid composition was different from those of the intracellular ferredoxins, which were already known. the contents of non-heme i ...19816793564
[kinetic model of the operation of a 2-electron switch in the photosynthetic reaction center of bacteria].a mathematical model, describing the binary oscillation of the concentration of semiquinone form of the secondary acceptor (ubiquinone) in photosynthetic reaction center of purple bacteria is proposed. this model takes into account both the changes of the ubiquinone state when the chromatophores are subjected to short flashes of light, and the successive dark relaxation of the semiquinone form. the model allows to calculate such characteristics as the dependence of the flash number, the stationa ...19816795442
[study of chromophore dynamics by means of rayleigh scattering of mossbauer radiation].the temperature dependence of rayleigh scattering of mössbauer radiation was studied for two samples of the chromatophores with different relative humidity (p/ps = 0.35 and 0.94). new type of motion--the transitions between conformational substates was found above 200 degrees k. the model was developed to describe conformational motion in the membranes and membrane proteins. a new formula was derived for the debye--waller factor in accordance with this model. the model proposes the existence of ...19816795443
the effects of bivalent cations on ribulose bisphosphate carboxylase/oxygenase.the half-saturation constants for binding of the bivalent cations (mg2+, ni2+, co2+, fe2+ and mn2+) to ribulose bisphosphate carboxylase/oxygenase from glycine max and rhodospirillum rubrum were measured. the values obtained were dependent on the enzyme and the cation present, but were the same for both oxygenase and carboxylase activities. ribulose bisphosphate rather than its cation complex was the true substrate. the kinetic parameters vmax.(co2), vmax.(o2), km(co2), km(o2), and k1(o2) were d ...19816796054
[low-temperature device for fluorimetric studies]. 19816796132
lateral organization of proteins in the chromatophore membrane of rhodospirillum rubrum studied by chemical cross-linking.the organization of proteins in the chromatophore membrane, particularly of the reaction center and the light-harvesting polypeptide, was examined by the use of a hydrophobic and a hydrophilic cross-linking reagent, namely dsp (dithiobis-succinimidyl propionate) and glutaraldehyde. the linkage of proteins was studied by sds polyacrylamide pore gradient electrophoresis. dsp was shown to link proteins within the core of the membrane. the subunit h of the reaction center is linked with dsp at a low ...19816796574
inactivation of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum and spinach with the new affinity label 2-bromo-1,5-dihydroxy-3-pentanone 1,5-bisphosphate. 19816797428
fermentation and anaerobic respiration by rhodospirillum rubrum and rhodopseudomonas capsulata.rhodospirillum rubrum and rhodopseudomonas capsulata were able to grow anaerobically in the dark either by a strict mixed-acid fermentation of sugars or, in the presence of an appropriate electron acceptor, by an energy-linked anaerobic respiration. both species fermented fructose without the addition of accessory oxidants, but required the initial presence of bicarbonate before fermentative growth could begin. major products of r. rubrum fermentation were succinate, acetate, propionate, formate ...19826798016
[carbamyl phosphate and citrulline formation by phototrophic bacteria].the purple bacteria ectothiorhodospira shaposhnikovii and rhodospirillum rubrum are capable of synthesizing citrulline in the presence of ammonium hydrocarbonate, ornithine, atp and mg2+ ions. citrulline biosynthesis by these phototrophic bacteria is presumed to be catalysed by carbamate kinase and ornithine transcarbamoylase. therefore, certain phototrophic bacteria can assimilate carbon dioxide and ammonia for biosynthesis of amino acids, in particular, citrulline and, apparently, arginine.19816798373
propionate formation in rhodospirillum rubrum under anaerobic dark conditions.experiments with 14c labelled propionyl-coa, methylmalonyl-coa and succinyl-coa showed that these compounds are intermediates of propionate synthesis in fermentative metabolism of rhodospirillum rubrum. the rate of propionate and succinate production is dependent on the co2 concentration of the medium. there is, however, no evidence for a transcarboxylation, and high concentrations of propionate in the medium did not inhibit propionate synthesis as in the case in propionibacteria. pep-carboxykin ...19816798770
borate inhibits activation of inactive dinitrogenase reductase from rhodospirillum rubrum.borate and aminophenylboronic acid were tested as inhibitors of activation of inactive dinitrogenase reductase from rhodospirillum rubrum. inhibition was specific for activation because activity of the active form of the enzyme was not inhibited. inhibition showed the ph-dependence expected if borate inhibits by binding to cis-hydroxy groups of the modifying group found on the inactive enzyme.19816798967
modification of active site histidine in ribulosebisphosphate carboxylase/oxygenase. 19826800404
photooxidase system of rhodospirillum rubrum iii. the role of rhodoquinone and ubiquinone in the activity of preparations of chromatophores and photoreaction centers.the role of rhodoquinone and ubiquinone in the oxygen photoreducing (photooxidase) activity of rhodospirillum rubrum was investigated. the sole addition of purified rhodoquinone restored photooxidase activity in isolated chromatophores which had been extracted with organic solvents and which were apparently free of secondary acceptor ubiquinone. rhodoquinone also enhanced photooxidase activity in photoreaction center preparations from which secondary ubiquinone seemed to have been removed. those ...19826800786
regulation of rhodospirillum rubrum nitrogenase activity. properties and interconversion of active and inactive fe protein. 19826801038
2-bromoacetylaminopentitol 1,5-bisphosphate as an affinity label for ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum.2-bromoacetylaminopentitol 1,5-bisphosphate (bracnh-pentitol-p2) (an epimeric mixture of 2-bromoacetylamino-2-deoxy-d-ribitol bisphosphate and 2-bromoacetylamino-2-deoxy-d-arabinitol 1,5-bisphosphate) has been synthesized from d-ribulose 1,5-bisphosphate by reductive amination with sodium cyanoborohydride followed by bromoacetylation of the resultant amine with bromoacetyl bromide. under conditions that favor full activation of the enzyme, ribulose bisphosphate carboxylase/oxygenase from rhodosp ...19826801050
reexamination of the binding site for pyridoxal 5'-phosphate in ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum.the high specificity of pyridoxal 5'-phosphate (plp) for an essential lysyl residue of ribulosebisphosphate carboxylase/oxygenase was confirmed, but half-of-sites reactivity was not observed in contrast to an earlier report [robison, p. d., whitman, w. b., waddill, f., riggs, a. f., & tabita, f. r. (1980) biochemistry 19, 4848-4853]. subsequent to reduction with [3h]borohydride and tryptic digestion of the enzyme inactivated by plp, the sole labeled peptide was purified by successive chromatogra ...19826803834
[analysis of the kinetics of transitional processes in biophysical research using a minicomputer]. 19826803850
development and growth of photosynthetic membranes of rhodospirillum rubrum.in cell-free extracts from low-aeration suspensions of rhodospirillum rubrum strain g-9, bacteriochlorophyll a was distributed in two bands after rate-zone sedimentation in sucrose density gradients. from the physicochemical properties of these fractions, it was concluded that the upper band consisted of small membrane fragments, whereas the major band was composed of fragmented vesicular intracytoplasmic membrane (chromatophores). after a pulse with l-[35s]methionine, apparent polypeptide subun ...19826804438
efficiency of light-driven metabolite transport in the photosynthetic bacterium rhodospirillum rubrum.an evaluation of the efficiency of the l-alanine and l-malate transport systems was undertaken with the photosynthetic bacterium rhodospirillum rubrum grown on the amino acid whose uptake was measured. an all-glass apparatus was constructed for measuring transport activity under anaerobic conditions. l-alanine transport activity decreased under conditions of mg2+ depletion. when cells were allowed to become inactive by suspending them in the dark in mg2+-free buffer, full activity could be resto ...19826804443
[reversible effect of intensive light on photobiochemical properties of rhodospirillum rubrum chromatophores].the effect of high intensity (photosynthesis-saturating) light on the optical properties of the bacteriochlorophyll and the light-induced h+ uptake by r. rubrum chromatophores was studied. it was shown that under aerobic conditions illumination causes reversible inhibition (in the dark) of the chromatophore ability for the light-induced uptake of h+, a reversible inhibition of the photosynthetical reaction center function and irreversible bleaching of the antennal bacteriochlorophyll. a kinetic ...19826805518
effect of light intensity and inhibitors of nitrogen assimilation on nh4+ inhibition of nitrogenase activity in rhodospirillum rubrum and anabaena sp.nitrogenase activity in rhodospirillum rubrum was inhibited by nh4+ more rapidly in low light than in high light. furthermore, the nitrogenase of cells exposed to phosphorylation uncouplers was inhibited by nh4+ more rapidly than was the nitrogenase of controls without an uncoupler. these observations suggest that high levels of photosynthate inhibit the nitrogenase inactivation system. l-methionine-dl-sulfoximine, a glutamine synthetase inhibitor, prevented nh4+ from inhibiting nitrogenase acti ...19826807962
photosynthetic bacterial reaction centers: interactions among the bacteriochlorophylls and bacteriopheophytins. 19826808895
[adenylate cyclase from a phototrophic organism]. 19826809439
comparison of active and inactive forms of iron protein from rhodospirillum rubrum.the fe protein of nitrogenase from rhodospirillum rubrum was purified in its active and inactive forms. it is shown that the inactive form exists as a two-subunit modified form of the enzyme as previously reported [ludden & burris (1978) biochem. j. 175, 251--259]. in contrast, the active form exists as a single-subunit unmodified form of the enzyme. the upper subunit (on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis) of the inactive form was shown to contain at least the phosphate ...19826810874
purification and mn2+ activation of rhodospirillum rubrum nitrogenase activating enzyme.the fe protein activating enzyme for rhodospirillum rubrum nitrogenase was purified to approximately 90% homogeneity, using de52-cellulose chromatography and sucrose density gradient centrifugation. activating enzyme consists of a single polypeptide of molecular weight approximately 24,000. atp was required for catalytic activity, but was relatively ineffective in the absence of mg2+. when the concentration of mgatp2- was held in excess, there was an additional requirement for a free divalent me ...19826813313
expression of the activating enzyme and fe protein of nitrogenase from rhodospirillum rubrum.activating enzyme (ae) is responsible for the in vitro activation of inactive fe protein of nitrogenase from rhodospirillum rubrum cells cultured anaerobically with glutamate as the n source. the expression of fe protein and ae was examined in r. rubrum cultured photosynthetically or aerobically on media containing malate as the carbon source. one of the following n sources was used in each culture: glutamate, glutamine, limiting ammonia, high ammonia, glutamate plus histidine, and high ammonia ...19826813314
cytochemical localization and measurement of aerobic 3,3'-diaminobenzidine oxidation reactions in photosynthetically grown rhodospirillum rubrum.photoheterotrophically grown rhodospirillum rubrum mutant c oxidized 3,3'-diaminobenzidine (dab) by two aerobic reactions. one reaction was light dependent. the other respiratory reaction occurred in the dark and could be inhibited by 0.1 m kcn. dab was not oxidized under anaerobic conditions. cytochemical results, obtained by reacting viable cells with dab, indicated that the two reactions were associated with different regions of the cellular membrane system. under dark conditions, oxidized da ...19826813374
pyruvate-dependent diauxic growth of rhodospirillum rubrum in light.when rhodospirillum rubrum mutant c was first exposed to radiant energy after long-term anaerobic dark growth, the cells often exhibited a diauxic growth response. this happened with pyruvate in the medium and when cultures were exposed to a less-than-growth-saturating white light intensity of about 6,460 lx. under the growth-saturating light condition, mutant c photometabolized and growth was not affected by na hypophosphite, an inhibitor of pyruvate fermentation. in lower intensity light, in w ...19826815163
heat activation of the fe protein of nitrogenase from rhodospirillum rubrum.the fe protein of nitrogenase from rhodospirillum rubrum isolated in the inactive form was found to be activated in vitro by heating. this heat activation was dependent upon temperature, ph, and enzyme concentration. during activation by heating, a change in the subunit composition of fe protein was observed on sodium dodecyl sulfate gels. the upper subunit decreases and the lower subunit increased. all components of the modifying group on inactive fe protein appear to be lost upon heat activati ...19826815184
change in subunit composition of the iron protein of nitrogenase from rhodospirillum rubrum during activation and inactivation of iron protein.the subunit composition of the fe protein of nitrogenase from rhodospirillum rubrum during activation and inactivation was investigated. it was found that the upper subunit (on gel electrophoresis) of the two-subunit fe protein was converted into the lower subunit during activation in vitro. when the fe protein was inactivated in vivo by the addition of nh4cl and alpha-oxoglutarate to the cells, a phosphate-labelled upper band appeared. during activation in vitro by the activating enzyme, some o ...19826816216
ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. 19826818424
protein liganding to the activator cation of ribulosebisphosphate carboxylase.spinach leaf ribulosebisphosphate carboxylase forms a quaternary complex with co2, carboxyarabinitol bisphosphate, and cr2+ or co2+. oxidation of the cation in these complexes produces a protein--cation adduct which is sufficiently stable to be chromatographically isolated after enzyme denaturation. while stoichiometric levels of slowly exchanging cation can be specifically trapped after addition of protein denaturants as well as a vast molar excess of mg2+, neither co2 nor carboxyarabinitol bis ...19826818984
purification and properties of chlorophyllase from greened rye seedlings.1. chlorophyllase [ec 3.1.1.14] was extracted from the acetone-dried powder of the chloroplasts of greened rye seedlings with 1% cholate, and purified 870-fold with a yield of about 30%. the purification procedure was composed of fractionations with acetone and ammonium sulfate, and hydrophobic chromatography on a phenyl-sepharose cl-4b column. 2. the purified enzyme was pure as analyzed by molecular-sieve chromatography and isoelectric electrophoresis. it had an isoelectric point of 4.5 and a m ...19826819291
purification and sequencing of cyanogen bromide fragments from ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. 19826819814
consensus structure and evolution of 5s rrna.a consensus structure model of 5s rrna presenting all conserved nucleotides in fixed positions has been deduced from the primary and secondary structure of 71 eubacterial, archaebacterial, eukaryotic cytosolic and organellar molecules. phylogenetically related groups of molecules are characterized by nucleotide deletions in helices iii, iv and v, and by potential base pair interactions in helix iv. the group-specific deletions are correlated with the early branching pattern of a dendrogram calcu ...19836835839
nitrogen metabolism in the phototrophic bacteria rhodocyclus purpureus and rhodospirillum tenue.studies of the nitrogen nutrition and pathways of ammonia assimilation in rhodocyclus purpureus and rhodospirillum tenue have shown that these two seemingly related bacteria differ considerably in aspects of their nitrogen metabolism. when grown photoheterotrophically with malate as carbon source, r. purpureus utilized only nh4+ or glutamine as sole nitrogen sources and was unable to fix n2. by contrast, r. tenue was found to utilize a variety of amino acids as nitrogen sources and was a good n2 ...19836863218
composition and development of the bacterial photosynthetic apparatus. 19817032006
peptidoglycan of rhodopseudomonas viridis: partial lack of n-acetyl substitution of glucosamine.a lack of at least 70% of n-acetyl substitution of glucosamine in the glycan strands of the peptidoglycan from the gram-negative bacterium rhodopseudomonas viridis is reported. a disaccharide, very likely glcn beta(1 leads to 4) mur, was observed in hydrolysates of the isolated peptidoglycan. the disaccharide was not observed when peptidoglycan was n-acetylated before hydrolysis. the peptidoglycan of r. viridis was resistant to lysozyme but became sensitive after n-acetylation with acetic anhydr ...19827054141
polar lipids in phototrophic bacteria of the rhodospirillaceae and chromatiaceae families.the polar lipids of photosynthetic purple bacteria of the genera chromatium, thiocapsa, thiocystis, ectothiorhodospira, rhodopseudomonas, rhodospirillum, and rhodomicrobium were analyzed. characteristic compositions of the polar lipids were found for most of the rhodospirillaceae and chromatiaceae species. phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin were the major phospholipids in most species. phosphatidylcholine was present as a major component in all species of the genus e ...19827076618
dinitrogen-fixing bacteria: computer-assisted identification of soil isolates.dinitrogen-fixing (acetylene-reducing) bacteria may be readily isolated from soils but extensive biochemical or immunobiological testing, or both, are required to identify them absolutely. a computer-assisted scheme for identification of nine genera of dinitrogen-fixing bacteria was developed and tested. the computer program is based on interpretation of the 70 biochemical tests of the api 20e and 50e, supplemented with tests for acetylene reduction, nitrate and nitrite reduction, catalase, oxid ...19807214218
[isolation and properties of the pigment-protein complex (protochlorophyllide - holochrome) from etiolated leaves of corn sprouts].a pigment -- protein complex was isolated from etiolated leaves of corn sprouts using treatment by the detergent triton x-100, ultracentrifugation and gel-filtration. the complex has a molecular weight of 50000 and upon illumination can convert protochlorophyllide (pchld) into chlorophyllide (chld). the low temperature fluorescence spectra of dark preparations reveal maxima of pchld 632 (photo-inactive form) and pchld 653 (photo-active form). upon illumination pchld 653 is converted into chld 68 ...19817248372
radioprotective and haemopoietic effects of some lipopolysaccharides from rhodospirillaceae species in mice.lipopolysaccharides (lps) from various rhodopseudomonas and rhodospirillum species were tested for their radioprotective efficiency against x-irradiation and for their influence on the growth of spleen colony forming units (cfu-s) in mice. the lps from rhodopseudomonas gelatinosa dr2 gave a high survival rate. it also favoured cfu-s formation and erythroid differentiation.19817327249
2-carboxy-d-hexitol 1,6-bisophosphate: an inhibitor of d-ribulose 1,5-bisphosphate carbosylase/oxygenase. 19807362236
labeling of chromatophore membranes and reaction centers from the photosynthetic bacterium rhodospirillum rubrum with the hydrophobic marker 5-[125i]iodonaphthyl-1-azide..chromatophores of the photosynthetic bacterium rhodospirillum rubrum and isolated reaction centers were labeled with the lipophilic membrane marker 5-[125i]iodonaphthyl-1-azide. the two smaller reaction center proteins l and m bind more label than the larger subunit h, a fact supporting the proposed localisation of the 3 subunits obtained with hydrophilic labels. besides these integral proteins the lipids, among them mainly the pigments and the quinones, are highly labeled suggesting a hydrophob ...19807397129
primary structures of high potential, four-iron-sulfur ferredoxins from the pruple sulfur photosynthetic bacteria, thiocapsa roseopersicina and chromatium gracile. 19817451471
structure of the heptose region of lipopolysaccharies from rhodospirillum tenue.there is a common structure (core region) in the lipopolysaccharides of rhodospirillum tenue. it is composed of a branched trisaccharide of l-glycero-d-mannoheptose (and of 2-keto-3-deoxyoctonate), as revealed by methylation analyses of degraded polysaccharides of four different r. tenue strains. the structure is similar or might even be identical to the inner core of enterobacterial o antigens. in addition, each of the four r. tenue lipopolysaccharides contains a strain-specific region that con ...19817462142
lipopolysaccharide of rhodospirillum salinarum 40: structural studies on the core and lipid a region.the structural elucidation of lipid a of the cell wall lipopolysaccharide (lps) of rhodospirillum salinarum 40 by chemical methods and laser desorption mass spectrometry revealed the presence of a mixed lipid a composed of three different 1,4'bisphosphorylated beta (1 --> 6)-linked backbone hexosaminyl-hexosamine disaccharides, i.e. those composed of glcn --> glcn, 2,3-diamino-2,3-dideoxy-d-glc-(dag --> dag, and dag --> glcn. lipid a of r. salinarum contained preferentially 3-oh-18:0 and 3-oh-14 ...19957487334
proton-translocating nicotinamide nucleotide transhydrogenase. reconstitution of the extramembranous nucleotide-binding domains.the nicotinamide nucleotide transhydrogenase of bovine mitochondria is a homodimer of monomer m(r) = 109,065. the monomer is composed of three domains, an nh2-terminal 430-residue-long hydrophilic domain i that binds nad(h), a central 400-residue-long hydrophobic domain ii that is largely membrane intercalated and carries the enzyme's proton channel, and a cooh-terminal 200-residue-long hydrophilic domain iii that binds nadp(h). domains i and iii protrude into the mitochondrial matrix, where the ...19957499307
ionic channel activity induced by fusion of rhodospirillum rubrum chromatophores with a planar bilayer lipid membrane.the present work concerns mechanisms of ionic conductivity of photosynthetic membranes. it is shown that reconstitution of vesicles of photosynthetic membranes (chromatophores) of purple bacteria rhodospirillum rubrum into a planar bilayer lipid membrane leads to fluctuations of current showing the existence of a channel with a predominant conductance of approximately 230 ps in the presence of 100 mm kcl. measurements under the conditions of kcl gradient prove that this channel is cation selecti ...19947506216
expression of tfx and sensitivity to the rhizobial peptide antibiotic trifolitoxin in a taxonomically distinct group of alpha-proteobacteria including the animal pathogen brucella abortus.three phylogenetically distinct groups within the alpha-proteobacteria which differ in trifolitoxin sensitivity are described. trifolitoxin sensitivity was found in strains of agrobacterium, brucella, mycoplana, ochrobactrum, phyllobacterium, rhodobacter, rhodopseudomonas, rhodospirillum, and rhizobium. strains of agrobacterium, brucella, phyllobacterium, rhizobium, and rhodospirillum were capable of producing trifolitoxin upon conjugal transfer of tfxabcdefg.19947527627
4-hydroxyphenethyl alcohol--a new cytokinin-like substance from the phototrophic purple bacterium rhodospirillum rubrum 1r.three compounds with cytokinin activity have been isolated from the medium of rhodospirillum rubrum grown photosynthetically. two n-6 aminopurine cytokinins revealed in the medium were identical with those obtained from r. rubrum cells previously. the third compound with cytokinin activity in amaranthus caudatus bioassay proved to be a simple phenolic compound with elemental composition c8h10o2. this cytokinin-like substance according to absorption spectra, mass spectrometry and 1h nmr spectra d ...19957539770
conformational dynamics of a mobile loop in the nad(h)-binding subunit of proton-translocating transhydrogenases from rhodospirillum rubrum and escherichia coli.transhydrogenase catalyses the reversible transfer of reducing equivalents between nad(h) and nadp(h) to the translocation of protons across a membrane. uniquely in rhodospirillum rubrum, the nad(h)-binding subunit (called ths) exists as a separate subunit which can be reversibly dissociated from the membrane-located subunits. we have expressed the gene for r. rubrum ths in escherichia coli to yield large quantities of protein. low concentrations of either trypsin or endoproteinase lys-c lead to ...19957556167
purification, primary structure, and evolution of cytochrome c-550 from the magnetic bacterium, magnetospirillum magnetotacticum.cytochrome c-550 was purified from magnetospirillum magnetotacticum to an electrophoretically homogeneous state, and some of its properties were determined. the cytochrome showed absorption peaks at 528 and 409 nm in the oxidized form, and at 550, 521, and 414 nm in the reduced form. its midpoint redox potential at ph 7.0 was determined to be +289 mv. the primary structure of cytochrome c-550 was determined. cytochrome c is composed of 97 amino acid residues, and its molecular weight was calcula ...19957575096
influence of charge and polarity on the redox potentials of high-potential iron-sulfur proteins: evidence for the existence of two groups.we have investigated the hipips from ectothiorhodospira vacuolata (iso-1 and iso-2), chromatium vinosum, rhodocyclus gelatinosus, rhodocyclus tenuis (strain 2761), rhodopila globiformis, and rhodospirillum salinarum (iso-2) by direct electrochemistry. using a glassy carbon electrode with a negatively charged surface, direct, unpromoted electrochemistry is possible with the positively charged hipips. with the negatively charged hipips, the positively charged and flexible bridging promoter poly(l- ...19957578075
the single-ring thermoanaerobacter brockii chaperonin 60 (tbr-el7) dimerizes to tbr-el14.tbr-es7 under protein folding conditions.chaperone proteins assist in the folding of some newly synthesized proteins and inhibit protein aggregation. the thermoanaerobacter brockii chaperonin proteins (tbr-el and tbr-es) have recently been purified and characterized [truscott, w.n., høj, p. b., & scopes, r. k. (1994) eur. j. biochem. 222, 277-284]; tbr-el was a single seven-membered toroid, unlike most groels which exist as double toroids. using high-resolution gel filtration chromatography, we have resolved the purified tbr-el into si ...19957578105
Displaying items 1201 - 1300 of 2252