differential effects of metal ions on rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase and stoichiometric incorporation of hco3- into a cobalt(iii)--enzyme complex.mg2+ or mn2+ ions supported both the carboxylase and oxygenase activities of the rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase. for the carboxylase reaction, mn2+ supported 25% of the maximum activity obtained with mg2+; oxygenase activity, however, was twice as great with mn2+ as compared to that with mg2+. a further differential effect was obtained with co2+. co2+ did not support carboxylase activity and, in fact, was a strong inhibitor of mg2+-dependent carboxylase activity ...1979115489
two regimens of electrogenic cyclic redox chain operation in chromatophores of non-sulfur purple bacteria. a study using antimycin a.antimycin a causes a biphasic suppression of the light-induced membrane potential generation in rhodospirillum rubrum and rhodopseudomonas sphaeroides chromatophores incubated anerobically. the first phase is observed at low antibiotic concentrations and is apparently due to its action as a cyclic electron transfer inhibitor. the second phase is manifested at concentrations which are greater than 1--2 mum and is due to uncoupling that may be connected with an antibiotic-induced dissipation of th ...1979116681
[photoformation of free radicals in the system bacteriochlorophyll--p-benzoquinone]. 1975166805
short-lived delayed luminescence of photosynthetic organisms. i. nanosecond afterglows in purple bacteria at low redox potentials.a combined study of emissions of purple bacteria rhodospirillum rubrum, ectothiorhodospira shaposhnikovii and thiocapsa roseopersicina was performed under conditions of low potential. it has been shown that a considerable part of the emission represents a delayed luminescence with a lifetime of about 5 ns and an activation energy delta e = 0.05 +/- 0.03 ev. intensity of this delayed luminescence is approximately equal to that of prompt fluorescence. it diminishes as temperature decreases and als ...1979116682
disintegration of rhodospirillum rubrum chromatophore membrane into photoreaction units, reaction centers, and ubiquinone-10 protein with mixture of cholate and deoxycholate.1. the membrane of rhodospirillum rubrum chromatophores was disintegrated with mild detergents (cholate and deoxycholate) in order to study the spatial arrangement of the functional proteins in the photochemical apparatus and the electron transport system in the membrane. 2. the components solubilized from the membrane by a mixture of cholate and deoxycholate (c-doc) were separated into four fractions by molecular-sieve chromatography in the presence of c-doc; they were designated as f1, f2, f3, ...1979118165
removal of an adenine-like molecule during activation of dinitrogenase reductase from rhodospirillum rubrum.during the activation of the inactive dinitrogenase reductase from rhodospirillum rubrum, an adenine-like molecules is lost and phosphate is found on both active and inactive forms of the protein. atp and divalent metals are required for activation of the reduced protein, but atp is not required for activation of phenazine methosulfate-oxidized dinitrogenase reductase. snake venom diesterase and spleen diesterase have no effect on the inactive protein; alkaline phosphatase removes phosphate from ...1979118462
[characterization of lipase activity in a yeast of the genus rhodotorula (rh. rubra)].lipase activity of whole cells of rh. rubra has been localized in a particular fraction rich in walls and in isolated cell walls. the enzyme activity has been determinated with olive oil and the triglyceride fraction of olive oil as substrats. gas chromatography of fatty acids and triglycerides isolated after enzyme hydrolysis shows that the action of rh. rubra is not only limited to a simple hydrolysis of the substrate. the triglyceridase activity level is dependent of the phosphate content of ...1977143999
interaction of a coupling factor from rhodospirillum rubrum with coupling factor deficient chromatophores.a coupling factor necessary for the photophosphorylation and mg2+-atpase activities in rhodospirillum rubrum chromatophores has been separated from these particles. although the redox potential of coupling factor deficient chromatophores is slightly more oxidized than of the control, the addition of the coupling factor for reconstitution does not alter the redox potential. phenazine methosulfate cannot restore or significantly enhance the photophosphorylation activities of uncoupled or reconstit ...1975125569
immunological and fluorescence studies with the coupling factor atpase from rhodospirillum rubrum.1. purification of the coupling factor atpase from rhodospirillum rubrum has been achieved by a combination of a previously described procedure with chromatography on deae-sephadex a50. 2. identification of the coupling factor atpase during purification, and estimation of the relative amount of the enzyme in each fraction was greatly simplified by utilization of its unusual fluorescence. 3. preparations of r. rubrum coupling factor atpase injected into rabbits yielded antisera which were suitabl ...1975126080
the photogeneration of superoxide by isolated photoreaction center from rhodospirillum rubrum. 1975173311
a spin-label study of biological membranes with special emphasis on calcium-induced lateral phase separation. 1976176878
regulatory properties of the citrate synthase from rhodospirillum rubrum.citrate synthase, purified 600-fold from rhodospirillum rubrum, is activated by kcl and inhibited by atp and nadh; the effect of the latter inhibitor is completely counteracted by amp and partially counteracted by kcl.1976178526
inhibition of the proton-translocating adenosine triphosphatase from chromatophores of photosynthetic bacteria by free bivalent cations and adenosine triphosphate [proceedings]. 1977144630
coupling factor atpase complex of rhodospirillum rubrum. purification and properties of a reconstitutively active single subunit. 1977144735
inhibition of energy conservation reactions in chromatophores of rhodospirillum rubrum by antibiotics. 1978147053
the interactions of coupling atpases with nucleotides. 1978147104
coupling factor adenosine-5'-triphosphatase from rhodospirillum rubrum: a simple and rapid procedure for its purification.when photosynthetic membranes from rhodospirillum rubrum, devoid of loosely bound small molecules and proteins, were passed through a french-pressure cell, the enzyme adenosine-5'-triphosphatase (ec (atpase) was released into the soluble fraction. the solubilized atpase was purified to homogeneity. in many respects it behaved like the enzyme purified by other workers, but it also hydrolyzed mg-atp with a small, but significant rate. furthermore, it was much more stable. maximal restora ...1976183408
immunological and reconstitution studies on the adenosine triphosphatase complex from rhodospirillum rubrum.studies on restoration of membrane-bound adenosinetriphosphatase (atp phosphohydrolase, ec from rhodospirillum rubrum show that the delta-subunit is capable of binding to the f1 factor or to the f0 moiety of the f0-f1 atpase complex. this subunit is thus likely involved in linking the f0 and f1 factor. during solubilization of the oligomycin-sensitive f0-f1 atpase complex with triton x-100 the detergent becomes specifically associated with the lipophilic f0 part of the enzyme complex. c ...1979153155
investigation of the structure of the reaction center in photosynthetic bacteria by optical detection of triplet state magnetic resonance. 1976183778
bound nucleotides and phosphorylation in rhodospirillum rubrum. 1979155454
purification, subunit structure, and kinetics of the chloroform-released f1atpase complex from rhodospirillum rubrum and its comparison with f1atpase forms isolated by other methods.a stable and homogeneous adenosine-5'-triphosphatase (atpase, ec has been solubilized from rhodospirillum rubrum (r. rubrum) chromatophores by chloroform extraction. purification of the ca2+-dependent atpase activity was 200-fold. ca2+ can be replaced by mg2+, cd2+, and mn2+. the km for ca-atp (0.17 mm) is increased about 5-fold during solubilization of the enzyme, whereas the km values for mg-atp (0.029 mm) and cd-atp (0.014 mm) are not affected. the chloroform-released atpase has a mo ...1979155949
preparation of the soluble atpase from mitochondria, chloroplasts, and bacteria by the chloroform technique. 1979156841
properties of the f0f1 atpase complex from rhodospirillum rubrum chromatophores, solubilized by triton x-100.1. a cold-stable oligomycin-sensitive f0f1 atpase complex from chromatophores of rhodospirillum rubrum fr 1 was solubilized by triton x-100 and purified by gel filtration. 2. the f0f1 complex is resolved by sodium dodecyl sulfate electrophoresis into 14 polypeptides with approximate molecular weights in the range of 58000--6800; five of these polypeptides are derived from the f1 moiety of the complex which carries the catalytic centers of the enzyme. 3. the purified f0f1 complex is homogeneous a ...1979157277
coupling factors atpases from photosynthetic bacteria. 1976134033
near-infrared magnetic circular dichroism of cytochrome c'.the near-infrared magnetic circular dichroism (mcd) of rhodospirillum rubrum, chromatium vinosum, and rhodopseudomonas palustris cytochromes c' are reported. the spectra of the reduced protein are very similar to those of deoxymyoglobin. the spectra of the oxidized proteins in the pd range 1-13 can be analyzed on the basis of four species a, b, c, and d. the existence of nine species, reported in a recent electron paramagnetic resonance study, is not substantiated. the mcd spectra support the as ...1977192272
stereochemistry of the porphyrin-protein bond of cytochrome c. stereochemical comparison of rhodospirillum rubrum, yeast, and horse heart porphyrins c.porphyrins c have been obtained from rhodospirillum rubrum cytochrome c2, yeast cytochrome c, and horse heart cytochrome c and compared using proton magnetic resonance and circular dichroism. identity of the spectra establishes that chemically and stereochemically the three porphyrins c are identical. since the stereochemistry of the porphyrin alpha-thioether linkage is not affected in the conversion to porphyrin c, the stereochemistry at the porphyrin alpha-thioether bonds among the correspondi ...1977192273
purification of the energy-transducing adenosine triphosphatase complex from rhodospirillum rubrum.the oligomycin- and n,n'-dicyclohexylcarbodiimide-sensitive adenosine triphosphatase complex extracted with triton x-100 from the chromatophores of rhodospirillum rubrum was extensively purified. the purification procedure included (diethylamino)ethylcellulose chromatography and glycerol gradient centrifugation. the specific activity of mg2+-dependent atp hydrolysis in the purified preparation increased about 11-fold, while that of ca2+-dependent atp hydrolysis increased 50-fold as compared with ...1979157774
[isolation and characterization of a membrane-bound pyruvate dehydrogenase complex from the phototrophic bacterium rhodospirillum rubrum (author's transl)].the pyruvate dehydrogenase complex from the photosynthetic bacterium rhodospirillum rubrum was associated with the membrane fraction both in heterotrophically and photosynthetically grown cells. the complex was separated from the membranes and partially purified by precipitation with mgso4 and gelfiltration through sepharose 4b. the purified complex had a specific activity of 1.5-2mumol/min-mg protein and contained the following partial activities: pyruvate dehydrogenase (ec, dihydrolip ...1977195415
coupling factor atpase complex of rhodospirillum rubrum. purification and characterization of an oligomycin and n,n'-dicyclohexylcarbodiimide-sensitive (ca+ + mg2+) atpase complex sensitive to the energy transfer inhibitors oligomycin, dicyclohexylcarbodiimide and venturicidin has been solubilized from rhodospirillum rubrum chromatophores with triton x-100 and further purified by centrifugation on a glycerol gradient. the partially purified rrfo . f1 contains 13 distinct polypeptide subunits, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, including the subunits of the oligomycin-sensitive, water-soluble rrf1 atpase. the atpase ...1979158383
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
isolation and characterization of bound ion-sulfur proteins from bacterial photosynthetic membranes. i. ferredoxins iii and iv from rhodospirillum rubrum chromatophores. 1977199587
isolation and characterization of bound ion-sulfur proteins from bacterial photosynthetic membranes. ii. succinate dehydrogenase from rhodospirillum rubrum chromatophores. 1977199588
a novel electron paramagnetic resonance signal associated with the 'primary' electron acceptor in isolated photochemical reaction centers of rhodospirillum rubrum. 1977200472
reduction kinetics of bacterial cytochromes c2. 1977202201
separation of respiratory reactions in rhodospirillum rubrum: inhibition studies with 2-hydroxydiphenyl.1. respiration of chemotrophically and phototrophically grown rhodospirillum rubrum is inhibited by 2-hydroxydiphenyl. 2. membrane-bound nadh oxidase and nadh: cytochrome c reductase are inhibited also. the inhibitor constant for both reactions (ki) is 0.075 plus or minus 0.012 mm. nadh dehydrogenase is not inhibited significantly. 3. the inhibition of succinate:cytochrome c reductase is associated for chemotrophic membranes with ki equals 0.22 plus or minus 0.03 mm and for phototrophic membrane ...1975164937
facile assay of enzymes unique to the calvin cycle in intact cells, with special reference to ribulose 1,5-bisphosphate carboxylase. 1978204219
influence of light on the epr-detectable, electron transport components in whole cell rhodospirillum rubrum. 1975165557
models for antenna and reaction center chlorophylls. 1975166592
extracellular hydrogenase from photosynthetic bacterium, rhodospirillum rubrum.with rhodospirillum rubrum, hydrogenase was found to exist partly as an extracellular enzyme in the culture medium. after 4-day cultivation, the total activity and the specific activity of the enzyme in the medium were about 10 times and 230 times as high as those in the crude extract obtained from disrupted cells. the time course for the production of hydrogenase during cultivation was studied.1979115852
isolation of a membrane protein from r rubrum chromatophores and its abnormal behavior in sds-polyacrylamide gel electrophoresis due to a high binding capacity for sds.a membrane protein insoluble in water was isolated by gel chromatography in the presence of 0.1% sodium dodecyl sulfate (sds) from chromatophores of a photosynthetic bacterium, rhodospirillum rubrum. this is one of the major membrane proteins of the chromatophore. the protein was found to bind about four grams of sds per gram, a value which is more than twice the amount generally observed with protein polypeptides derived from water-soluble globular proteins. the electrophoretic behavior of the ...197897280
dichroism of bacteriochlorophyll in chromatophores of photosynthetic bacteria.the dichroism was measured in films of air-dried and, consequently, flattened chromatophores of chromatium vinosum, rhodopseudomonas sphaeroides and rhodospirillum rubrum. the values (deltaa/a) of dichroism in c. vinosum were found to be -1.05 at 590 nm and 0.75 in the near infrared region. the values of dichroism in r. sphaeroides were -0.70 at 590 nm and 0.80 at 870 nm. the values of dichroism in r. rubrum were -1.45 at 590 nm and 0.97 at 870 nm.197897281
phenazine methosulfate mediated photoinactivation of some energy linked reactions in rhodospirillum rubrum. 1978208532
enzymes of glycollate formation and oxidation in two members of the rhodospirillacae (purple non-sulphur bacteria).1. phototrophic cultures of rhodomicrobium vanielii do not excrete glycollate when gassed anaerobically with nitrogen plus carbon dioxide, although the addition of alpha-hydroxy-2-pyridine methanesulphonate (hpms) results in the excretion of a trace amount of glycollate. the inclucion of low amounts of oxygen in this gas mixture results in marked glycollate excretion, higher rates occurring in the presence of hpms. 2. cell extracts of rhodomicrobium vannielii, and also of rhodospirillum rubrum, ...1975168831
conformational energy refinement of horse-heart ferricytochrome c.the reported x-ray structure of horse-heart ferricytochrome c has been refined by conformational energy calculations, using a three-stage computational procedure. in stage i, the atomic positions are adjusted to conform to idealized bond lengths and bond angles characteristic of small amino acid derivatives, while yet remaining as close as possible to the x-ray coordinates. in stage ii, atomic overlaps are eliminated by adjusting the backbone and side-chain dihedral angles to minimize the nonbon ...1975169878
letter: optically detected zero-field magnetic resonance studies of the photoexcited triplet state of the photosynthetic bacterium rhodosopirillum rubrum. 1975171297
role of ubiquinone-10 in electron transport system of chromatophores from rhodospirillum rubrum.the role of ubiquinone-10 in the activities for the reduction of free cytochrome c2 and bound cytochrome cc' by succinate was studied with chromatophores from a blue-green mutant (g-9) of rhodospirillum rubrum. 1. by a single extraction with isooctane, approximately 90% of ubiquinone-10 was easily removed from the chromatophores. in the extracted chromatophores, the activity for succinate-cytochrome c2 reduction decreased to 5-10% of the original activity. this depressed activity was mostly rest ...1975172493
characterization of two soluble ferredoxins as distinct from bound iron-sulfur proteins in the photosynthetic bacterium rhodospirillum an earlier investigation (shanmugam, k. t., buchanan, b. b., and arnon, d. i. (1972) biochim. biophys. acta 256, 477-486) the extraction of ferredoxin from rhodospirillum rubrum cells with the aid of a detergent (triton x-100) and acetone revealed the existence of two types of ferredoxin (i and ii) and led to the conclusion that both are membrane-bound. in the present investigation, ferredoxin and acid-labile sulfur analyses of photosynthetic membranes (chromatophores) and soluble protein ext ...1975172494
amino acid sequence of cytochrome c' from the purple photosynthetic bacterium rhodospirillum rubrum s1.the amino acid sequence of cytochrome c' from the purple photosynthetic bacterium rhodospirillum rubrum s1 has been determined and is consistent with homology to cytochrome c' from the nonphotosynthetic bacterium alcaligenes sp. ncib 11015. there is 29% identity in the chosen alignment of these two proteins. r. rubrum cytochrome c' is composed of a single peptide chain of 126 amino acid residues with a single heme covalently bound near the cooh terminus. there is no sequence similarity to mitoc ...1975172499
polarographic studies in presence of triton x-100 on oxidation-reduction components bound with chromatophores from rhodospirillum rubrum.polarographic studies on oxidation-reduction components bound with chromatophores from rhodospirillum rubrum were carried out at 24 degrees. 1. using a carbon-paste electrode as the working electrode, polarographic waves characteristic of oxidation-reduction components were observed in the presence, but not in the absence of triton x-100; these waves were therefore measured in the presence of the detergent. 2. at least two kinds of oxidation-reduction components were detectable, having different ...1976181368
preparation of cytochrome c2 from rhodospirillum rubrum. 1976182031
the early formation of the photosynthetic apparatus in rhodospirillum rubrum.the time dependent assembly of the photosynthetic apparatus was studied in rhodospirillum rubrum after transfer of cells growing aerobically in the dark to low aeration. while bacteriochlorophyll (bchl) cellular levels increase continuously levels of soluble cytochrome c2 do not change significantly. absorption spectra of membranes isolated at different times after transfer reveal that incorporation of carotenoids lags behind incorporation of bchl. however, a carotenoid fraction exhibiting spect ...1976182100
ribulose 1,5-diphosphate carboxylase and cholorobium thiosulfatophilum.1. cell-free extracts of the photosynthetic bacterium cholorobium thiosulfatophilum, strains 8327 and tassajara, were assayed for ribulose 1,5-diphosphate (rudp) carboxylase and phosphoribulokinase--the two enzymes peculiar to the reductive pentose phosphate cycle. 2. rudp carboxylase was consistently absent in strain 8327. the tassajara strain showed a low rudp-dependent co2 fixation activity that was somewhat higher in cells following transatlantic air shipment than in freshly grown cells. the ...1976183616
thermodynamic properties of the reaction center of rhodopseudomonas viridis. in vivo measurement of the reaction center bacteriochlorophyll-primary acceptor intermediary electron carrier.the thermodynamic properties of redox components associated with the reaction center of rhodopseudomonas viridis have been characterized with respect to their midpoint potentials and relationship with protons. in particular a midpoint potential for the intermediary electron carrier acting between the reaction center bacteriochlorophyll and the primary acceptor has been determined. the rationale for this measurement was that the light-induced triplet/biradical epr signal would not be observed if ...1976183815
kinetics of populating and depopulating of the components of the photoinduced triplet state of the photosynthetic bacteria rhodospirillum rubrum, rhodopseudomonas spheroides (wild type), and its mutant r-26 as measured by esr in zero-field.optically detected esr spectra in zero magnetic field of the triplet state of three photosynthetic bacteria are presented. the zero field splitting parameters [d] and [e] and the widths of the resonances show small but significant differences for the three bacteria. the resonance lines are inhomogeneously broadened as demonstrated by hole-burning experiments. the populating probabilities and depopulating rates for the triplet sublevels have been measured. the populating kinetics are very similar ...1976183816
the effect of transfer from low to high light intensity on electron transport in rhodospirillum rubrum membranes.the effects of transfer from low to high light intensity on membrane bound electrontransport reactions of rhodospirillum rubrum were investigated. the experiments were performed with cultures which did not form bacteriochlorophyll (bchl) for about two cell mass doublings during the initial phase of adaptation to high light intensity. lack of bchl synthesis causes a decrease of bchl contents of cells and membranes. also, the cellular amounts of photosynthetically active intracytoplasmic membranes ...1976185976
function of three cytochromes in photosynthesis of whole cells of rhodospirillum rubrum as studied by flash spectroscopy. evidence for two types of reaction center.1. changes in the absorption spectrum induced by 10-mus flashes and continuous light of various intensities were studied in whole cells of rhodospirillum rubrum in the presence and absence of 2-n-heptyl-4-hydroxyquinoline-n-oxide(hoqno) and antimycin a. 2. three cytochromes, c-420 (cytochrome c2), c-560 (cytochrome b) and c-428 were photoactive and gamma and alpha peaks at 420 and 550, 428 and 560, and 428 and 551 nm, respectively; they were photooxidized following the flash with half times of 0 ...1976186114
magnetophotoselection applied to the triplet state observed by epr in photosynthetic bacteria. 1976187200
[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
phototaxis and membrane potential in the photosynthetic bacterium rhodospirillum rubrum.cells of the photosynthetic bacterium rhodospirillum rubrum cultivated anaerobically in light show phototaxis. the behavior of individual cells in response to the phenomenon is reversal(s) of the swimming direction when the intensity of the light available to them abruptly decreases. the tactic response was inhibited by antimycin, an inhibitor of the photosynthetic electron transfer system. the inhibitory effect of antimycin was overcome by phenazine methosulfate. motility of the cells was not i ...1977194880
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
structure and function of cytochromes c. 1977197877
comparative kinetic-ionic strength study of two differently charged cytochrome c: effects are limited to overall charge. 1977202274
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
preliminary crystallographic data for cytochromes c' of rhodopseudomonas capsulata and rhodospirillum molischianum. 1977204789
[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
adenylate kinase from rhodospirillum rubrum.a partial purification and some properties of adenylate kinase from the photosynthetic bacterium rhodospirillum rubrum are described.1978207554
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
characterization of the phototrap in photosynthetic bacteria. 1975237454
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
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
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
on the significance of electron transport systems for growth of rhodospirillum rubrum. 1978211972
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
[polyphosphate biosynthesis in rhodospirillum rubrum chromatophores].the chromatophores of rhodospirillum rubrum were found to synthesize in the light not only atp and pyrophosphate but also high molecular weight polyphosphates. biosynthesis of all studied compounds was inhibited by antimycin a, an inhibitor of the electron-transport photosynthetic chain. synthesis of high molecular weight polyphosphates is stimulated, while that of pyrophosphate is inhibited, in the conditions providing intensive synthesis of atp (in the presence of adp and in the absence of oli ...1976180387
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
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
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
[determination of the distance between charges following their photoseparation in chromatophores from r. rubrum]. 1979221054
anomalies in amino acid sequences of small cytochromes c and cytochromes c' from two species of purple photosynthetic bacteria. 1979221823
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
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
the chronoamperometric determination of homogeneous small molecule-redox protein reaction rates. 1979224724
properties of the solubilized membrane-bound hydrogenase from the photosynthetic bacterium rhodospirillum rubrum. 1979224815
linear dichroism of light-induced absorbance changes of reaction centers of rhodospirillum rubrum. 1977405251
[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
simple equipment for the growth of photosynthetic bacteria. 1977406256
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
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
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
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
[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
isolation of a photosynthetic strain of rhodospirillum rubrum with an altered reaction center. 1977409348
photosynthetic and respiratory electron flow in the dual functional membrane of facultative photosynthetic bacteria. 1978233518
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
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
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
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
[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
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
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
Displaying items 101 - 200 of 2252