Publications

picosecond detection of bchl-800 as an intermediate electron carrier between selectively-excited p870 and bacteriopheophytin in rhodospirillum rubrum relaction centers.		1978	97097
nitrogen fixation and hydrogen metabolism in photosynthetic bacteria.	the photosynthetic bacteria are found in a wide range of specialized aquatic environments. these bacteria represent important members of the microbial community since they are capable of carrying out two of the most important processes on earth, namely, photosynthesis and nitrogen fixation, at the expense of solar energy. since the discovery that these bacteria could fix atmospheric nitrogen, there has been an intensification of studies relating to both the biochemistry and physiology of this pr ...	1978	96875
flash-induced changes in the in vivo bacteriochlorophyll fluorescence yield at low temperatures and low redox potentials in carotenoid-containing strains of photosynthetic bacteria.	the changes in the in vivo bacteriochlorophyll fluorescence induced by a xenon flash at low temperatures (77--200 k) with the "primary" acceptor x chemically prereduced have been examined in whole cells of several species of photosynthetic bacteria which contain carotenoids absorbing in the visible part of the absorption spectrum. two groups of species with different behaviour could be distinguished. in both cases a flash-induced rise of the fluorescence yield was observed with x prereduced at 7 ...	1978	96856
bacteriochlorophyll fluorescence of purple bacteria at low redox potentials. the relationship between reaction center triplet yield and the emission yield.	this work describes fluorescence yield measurements in suspensions of strains of rhodospirillum rubrum and rhodopseudomonas sphaeroides in which the iron . quinone complex (x) was chemically reduced (state [pix-]; p is the reaction center bacteriochlorophyll dimer, i is the long wavelength bacteriopheophytin), and compares these with the fluorescence observed when all the traps are open (state [pix]) and with the fluorescence observed when all the traps are closed (state [p+ix]). at 77 k the amp ...	1978	96854
studies on regulatory functions of malic enzymes. v. comparative studies of malic enzymes in bacteria.	screening of four malic enzymes--nad-linked enzyme [ec 1.1.1.38], nad, nadp-linked enzyme [ec 1.1.1.39], nadp-linked enzyme [ec 1.1.1.40], and d-malic enzyme--was carried out with cell-free extracts of the following 16 strains of bacteria by the aid of sepharose 6b column chromatography: 9 strains of enteric bacteria, 3 strains of pseudomonas, alcaligenes faecalis, agrobacterium tumefaciens, rhodospirillum rubrum, and clostridium tetanomorphum. all the strains tested contained at least one malic ...	1978	96110
viability and endogenous substrates used during starvation survival of rhodospirillum rubrum.	cells of rhodospirillum rubrum were grown photoorganotrophically and chemoorganotrophically and then starved for organic carbon and combined nitrogen under four conditions: anaerobically in the light and dark and aerobically in the light and dark. illumination prolonged viability and suppressed the net degradation of cell material of phototrophically grown cells, but had no effect on chemotrophically grown cells that did not contain bacteriochlorophyll. the half-life survival times of carbohydra ...	1978	96087
lipophilic o-antigens in rhodospirillum tenue.	lipopolysaccharides of eight wild-type strains of the phototrophic bacterium rhodospirillum tenue have been analyzed. all of the lipopolysaccharides are highly lipophilic. the compositions of preparations obtained by the phenol-water or by the phenol-chloroform-petroleum ether procedure are very similar. the polysaccharide moiety, obtained by mild acid hydrolysis of lipopolysaccharide, consists mainly of aldoheptoses: l-glycero-d-mannoheptose is present in all strains, whereas d-glycero-d-mannoh ...	1977	95659
photooxidase system of rhodospirillum rubrum. i. photooxidations catalyzed by chromatophores isolated from a mutant deficient in photooxidase activity.	the aerobic photooxidations of reduced 2,6-dichlorophenolindophenol and of reaction-center bacteriochlorophyll (p-870) have been investigated in membrane vesicles (chromatophores) isolated from a non-phototrophic rhodospirillum rubrum strain. in aerobic suspensions of wild-type chromatophores, continuous light elicits an increase of the levels of 2,6-dichlorophenolindophenol and of oxidized p-870, which reach steady-state values shortly after the onset of illumination. in contrast, light induces ...	1977	64259
generation of electric current by chromatophores of rhodospirillum rubrum and reconstitution of electrogenic function in subchromatophore pigment-protein complexes.	lipoprotein complexes, containing (1) bacteriochlorophyll reaction centers, (2) bacteriochlorophyll light-harvesting antenna or (3) both reaction centers and antenna, have been isolated from chromatophores of non-sulphur purple bacteria rhodospirillum rubrum by detergent treatments. the method of reconstituting the proteoliposomes containing these complexes is described. being associtated with planas azolectin membrane, ptoteoliposomes as well as intact chromatophores were found to generate a li ...	1976	61042
postillumination adenosine triphosphate synthesis in rhodospirillum rubrum chromatophores. ii. stimulation by a k+ diffusion potential.	addition of valinomycin, nonactin, or monactin plus kcl in the dark to preilluminated chromatophores induced the synthesis of a large amount of atp. this stimulation of postillumination atp synthesis by a dark-imposed k+ diffusion potential was different from the stimulation caused by addition of permeant anions or cations in the light, since it increases when the ph of the light stage decreased from 8.0 to 6.0. it was thus most pronounced when the chromatophores were preloaded with protons but ...	1975	49352
origin of the atp formed during the light-dependent oxygen uptake catalyzed by rhodospirillum rubrum chromatophores.	the oxygen uptake which is observed when rhodospirillum rubrum chromatophores are illuminated under air and in the presence of reduced 2, 6-dichlorophenolindophenol (dcip), 2, 3, 5, 6-tetra-methyl-p-phenylenediamine (diaminodurene, dad) or n, n'-tetramethyl-p-phenylenediamine (tmdp) depends on the electron-donor concentration according to the equation of michaelis-menten. the apparent km for the donor is lowered by the electron-transfer inhibitor 2-heptyl-4-hydroxyquinoline-n-oxide (hqno) which ...	1975	47212
manganese, an essential trace element for n2 fixation by rhodospirillum rubrum and rhodopseudomonas capsulata: role in nitrogenase regulation.	nitrogenase (n(2)ase) from the photosynthetic bacterium rhodospirillum rubrum can exist in two forms, an unregulated form (n(2)ase a) and a regulatory form (n(2)ase r), the latter being identified in vitro by its need for activation by a mn(2+)-dependent n(2)ase activating system. the physiological significance of this mn(2+)-dependent n(2)ase activating system was suggested here by observations that growth of r. rubrum and rhodopseudomonas capsulata on n(2) gas (a condition that produces active ...	1979	42641
[shifts of the bacteriochlorophyll absorption band at 880 nm in chromatophores and subchromatophore pigment-protein complexes from rhodospirillum rubrum].	the redox potential dependency of the light-induced absorption changes of bacteriochlorophyll in the chromatophores and subchromatophore particles from rhodospirillum rubrum has been studied. the highest values of the absorption changes due to the bleaching of p870 and the blue shift of p800 are observed within the redox potential range of 360--410. at the potential values below 300 mv the 880 nm band of bacteriochlorophyll shifts to shorter wavelengths in the subchromatophore particles and to l ...	1979	41599
blue and red shifts of bacteriochlorophyll absorption band around 880 nm in rhodospirillum rubrum.	the redox potential dependence of the light-induced absorption changes of bacteriochlorophyll in chromatophores and subchromatophore pigment-protein complexes from rhodospirillum rubrum has been examined. the highest values of the absorption changes due to the bleaching of p-870 and the blue shift of p-800 in chromatophores and subchromatophore complexes are observed in the 360-410mv redox potential range. at potentials below 300 mv (ph 7.0), the 880 nm band of bacteriochlorophyll shifts to shor ...	1979	41575
the kinetics of photooxidation of c-type cytochromes by rhodospirillum rubrum reaction centers.		1979	41489
resolution and reconstitution of rhodospirillum rubrum pyridine dinucleotide transhydrogenase: chemical modification with n-ethylmaleimide and 2,4-pentanedione.		1979	39595
[activation and inhibition of photoinduced proton absorption in rhodospirillum rubrum chromatophores by detergents and solvents].	the effects of detergents (triton x-100) and solvents (diethyl ether, metanol) on the reversible light-induced proton uptake, photophosphorylation and band shift of the carotenoid in chromatophores from r. rubrum are described. all these compounds were found to stimulate the extent of light-induced proton uptake with subsequent inhibition when the concentrations were increased. stimulation of proton uptake is accompanied by inhibition of both phosphorylation and carotenoid absorbance shift.	1979	37926
the influence of energy-transfer inhibitors on proton permeability and photophosphorylation in normal and preilluminated rhodospirillum rubrum chromatophores.	(1) chromatophores were preilluminated in the presence of phenazine methosulphate or diaminodurene, and without phosphorylation substrates; next they were transferred to fresh medium and assayed for light-induced proton uptake, light-induced 9-aminoacridin fluorescence quenching, and photophosphorylation. (2) preillumination in the presence of phenazine methosulphate or diaminodurene causes an inhibition of the photophosphorylation rate. the presence of adp + mgcl2 + phosphate, or adp + mgcl2 + ...	1979	37903
role of the large and small subunits of ribulose-1,5-bisphosphate carboxylase in the activation by co2 and mg2+.		1979	37245
proton nuclear magnetic resonance studies of rhodospirillum rubrum cytochrome.	rhodospirillum rubrum cytochrome c2 was studied by proton nuclear magnetic resonance at 220 mhz. assignments were made to the resonances of heme c by double-resonance techniques and by temperature-dependence studies. the aromatic resonances of trp-62 and tyr-70 of ferrocytochrome c2 were identified by spin-decoupling experiments. the resonances of the met-91 methyl group of the ferri- and ferrocytochromes were assigned by saturation-transfer experiments. the assignments are compared to those mad ...	1979	34433
isolation, characterization, and crystallization of ribulosebisphosphate carboxylase from autotrophically grown rhodospirillum rubrum.	serial culture of rhodospirillum rubrum with 2% co2 in h2 as the exclusive carbon source resulted in a rather large fraction of the soluble protein (greater than 40%) being comprised of ribulosebisphosphate carboxylase (about sixfold higher than the highest value previously reported). isolation of the enzyme from these cells revealed that it has physical and kinetic properties similar to those previously described for the enzyme derived from cells grown on butyrate. notably, the small subunit (w ...	1979	33152
dna-dependent rna and polyadenylic acid polymerase from phototrophically grown rhodospirillum rubrum.	dna-dependent rna and polyadenylic acid polymerases have been purified from phototrophic rhodospirillum rubrum. their properties have been found to be very similar to those of the previously reported heterotrophic r. rubrum enzymes. however, several important differences do exist between the enzymes from the phototrophic and the heterotrophic cells, such as the lack of response to added polyadenylic acid for poly a synthesis and the presence of the sigma subunit in the phototrophic enzymes. fur ...	1978	31974
reversible conversion from ca(2)+-atpase activity to mg(2)+- and mn(2)+-atpase activities of coupling factor purified from acetone powder of rhodospirillum rubrum chromatophores.	it is known that the coupling factor purified from the acetone powder of chromatophores from rhodospirillum rubrum shows atpase activity in the presence of ca(2)+, but not in the presence of mg(2)+ or mn(2)+. the present study deals with conditions, under which the ca(2)+-atpase activity is reversibly converted into mg(2)+- and mn(2)+-atpase activites with the purified coupling factor. 1. of the ph indicators tested, 6 kinds coverted the ca(2)+-atpase activity into mg(2)+- and mn(2)+-atpase acti ...	1978	30771
pms photo-inhibition in rhodospirillum rubrum membranes in the presence of permeant entities affecting either the deltapsi or the deltaph components of the protonmotive force.		1978	29789
affinity chromatography of h+-translocating adenosine triphosphatase isolated by chloroform extraction of rhodospirillum rubrum chromatophores. modification of binding affinity by divalent cations and activating anions.	1. atpase isolated from rhodospirillum rubrum by chloroform extraction and purified by gel filtration or affinity chromatography shows three bands (alpha, beta and gamma) upon electrophoresis in sodium dodecyl sulphate. 2. ca2+-atpase activity of the preparation is inhibited by aurovertin and efrapeptin but not by oligomycin. activity may be inhibited by treatment with 4-chloro-7-nitrobenzofurazan and subsequently restored by dithiothreitol. 3. the enzyme fails to reconstitute photophosphorylati ...	1978	27212
subcellular distribution and several properties of the camp enzyme system of phototrophic bacteria.	in the cells of the phototrophic bacteria rhodospirillum rubrum and rhodopseudomonas palustris the two enzymes of the camp system enzymes - adenylate cyclase and camp phosphodiesterase (pde) exist in a soluble and membrane-bound forms. after mild disruption of the cells (sonication up to 3 min) the activity of both enzymes is found in the chromatophores. in the cells of the two types of bacteria grown under anaerobic conditions soluble adenylate cyclase is predominant. in the cells of r. rubrum ...	1978	26430
modification of rhodospirillum rubrum ribulose bisphosphate carboxylase with pyridoxal phosphate. 1. identification of a lysyl residue at the active site.	ribulose 1,5-bisphosphate carboxylase isolated from rhodospirillum rubrum was strongly inhibited by low concentrations of pyridoxal 5'-phosphate. activity was protected by the substrate ribulose bisphosphate and to a lesser extent by other phosphorylated compounds. pyridoxal phosphate inhibition was enhanced in the presence of magnesium and bicarbonate, but not in the presence of either compound alone. concomitant with inhibition of enzyme activity, pyridoxal phosphate forms a schiff base with t ...	1978	26381
the proton pump is a molecular engine of motile bacteria.		1978	24186
resolution and reconstitution of rhodospirillum rubrum pyridine dinucleotide transhydrogenase. ii. solubilization of the membrane-bound component.	the rhodospirillum rubrum pyridine dinucleotide transhydrogenase system is comprised of a membrane-bound component and an easily dissociable soluble factor. active transhydrogenase complex was solubilized by extraction of chromatophores with lysolecithin. the membrane component was also extracted from membranes depleted of soluble factor. the solubilized membrane component reconstituted transhydrogenase activity upon addition of soluble factor. various other ionic and non-ionic detergents, inclu ...	1977	23085
light-induced ph changes and changes in absorbance of ph indicators in rhodospirillum rubrum chromatophores.	1. the light-induced ph change of chromatophore suspensions from rhodospirillum rubrum was stimulated significantly and similarly by kcl, nacl, licl, rbcl, cscl, mgcl2, mncl2, and cacl2. in the dark, the ph of chromatophore suspensions decreased immediately and markedly on adding these salts. 2. the light-induced ph change stimulated by kcl plus valinomycin was inhibited by licl and nacl, but not by rbcl. 3. the optimum ph values for light-induced ph change and photosynthetic atp formation were ...	1977	22540
light-dependent uptake of hydrogen ions in chloroplasts and chromatophores: effects of hearing, solvents and detergents.	the effects of heating, organic solvents and detergents on the light-dependent hydrogen ion uptake in chloroplasts and chromatophores and the coupled photophosphorylation were compared. it was shown that the membrane structure of the chromatophores is much more stable than that of the chloroplast thylacoids. the activation of the ph function in the chromatophores in the presence of low concentrations of diethyl ether and detergents was noted. the effects observed may be due to the changes in the ...	1977	22359
comparative study of nadp-reductase properties in two species of purple bacteria.	unlike rhodospirillum rubrum, the highly purified preparations of nadp-reductase thiocapsa roseopersicina are capable of reduction of cytochrome c though they do not catalyse diaphorase reaction in the presence of methyl viologen or benzyl viologen and nadh. t. roseopersicina reductase has more high temperature optimum (50-65 degrees) and more high thermal stability (65 degrees) and it is capable to catalyse diaphorase and menadione-reductase reactions under more high ph values (11.0-12.0) than ...	1977	20991
resonance raman study of the ph-dependent and detergent-induced structural alterations in the heme moiety of rhodospirillum rubrum cytochrome c'.	the resonance raman spectra and the structures of the heme moiety of rhodospirillum rubrum cytochrome c' were investigated for its five states characterized by absorption spectra; types-a and -n of the reduced form and types-i, -ii, and -iii of the oxidized form. the frequency of the ligand-sensitive raman line suggested the coordination of lysine (nepsilon) at the sixth position of the heme iron of type-n. the sixth ligand of type-iii was deduced to be either lysine or histidine but would not b ...	1977	20977
fermentative metabolism of pyruvate by rhodospirillum rubrum after anaerobic growth in darkness.	rhodospirillum rubrum grew anaerobically in darkness and fermented sodium pyruvate by a pyruvate formate-lyase reaction. during 30 min of anaerobic dark or light incubation with sodium pyrivate, crude extracts from fermentatively grown cells produced about 6 micronmol of acetylphosphate and formate per mg of protein in reactions performed at ph 8.3. cell extracts also catalyzed the exchange of sodium 14cformate into sodium pyruvate at an apparent ph optimum of 7.3 to 7.5, but only about 2.5 micr ...	1977	18439
multiple forms of dna-dependent rna and polyadenylic acid polymerases from heterotrophically grown rhodospirillum rubrum.	three, two major and one minor, distinct rna polymerases have been isolated and partially purified from heterotrophically grown rhodospirillum rubrum, a facultative photosynethetic bacterium. associated with each of these three enzymes is a distinct polyadenylic acid polyemrase. all of these enzyme activities are dependent on dna templates and are resistant to rifampicin and streptovaricin. the structural subunit composition, the response to various chemical compounds and dna templates, and the ...	1977	17456
adenosine-5'-phosphosulfate (aps) as sulfate donor for assimilatory sulfate reduction in rhodospirillum rubrum.	crude extracts of rhodospirillum rubrum catalyzed the formation of acid-volatile radioactivity from (35s) sulfate, (35s) adenosine-5'-phosphosulfate, and (35s) 3'-phosphoadenosine-5'-phosphosulfate. an enzyme fraction similar to aps-sulfotransferases from plant sources was purified 228-fold from rhodospirillum rubrum. it is suggested here that this enzyme is specific for adenosine-5'-phosphosulfate, because the purified enzyme fraction metabolized adenosine-5'-phosphosulfate; 3'-phosphoadenosine ...	1977	16577
interconversion of two kinetically distinct states of the membrane-bound and solubilised h+-translocating atpase from rhodospirillum rubrum.		1977	15868
electrochemical gradient of h+ ions as an immediate source of energy during bacteria movement.	an uncoupler of oxidative phosphorylation causes an instantaneous cessation of movement of bacteria rhodospirillum rubrum in the presence and in the absence of oligomycin. it is concluded that such cessation is not due to a decrease in the atp concentration but to the elimination of deltamicron-h+ by the uncoupler. the mobility of the bacteria does not practically change in the presence of acetate and is, to some extent, decreased after addition of valinomycin or penetrating cation of tetrapheny ...	1976	15648
camp phosphodiesterase from phototrophic bacteria rhodospirillum rubrum.	camp phosphodiesterase activity is discovered in supernatant of r. rubrum cell homogenate after centrifugation at 1000 g. the enzyme is highly active (5.62 nmoles/mg of protein per 1 min) at a broad ph range--from 7.0 to 9.0. the enzyme activity is strongly inhibited with caffeine and dithiotreitol and very significantly inhibited by ascorbic acid. the dependence of the enzyme activity on the incubation time and protein and substrate concentrations in the reaction mixture is estimated. camp phos ...	1976	14724
photoproduction of ammonium ion from n2 in rhodospirillum rubrum.	nh+4 excretion was undetectable in n2-fixing cultures of rhodospirillum rubrum (s-1) and nitrogenase activity in these cultures was repressed by the addition of 10 mm nh+4 to the medium. the glutamate analog, l-methionine-dl-sulfoximine (msx), derepressed n2 fixation even in the presence of 10 mm extracellular nh+4. when 10 mg msx/ml was added to cultures just prior to nitrogenase induction they developed nitrogenase activity (20% of the control activities) and excreted most of their fixed n2 as ...	1976	13753
growth of spirillum lipoferum at constant partial pressures of oxygen, and the properties of its nitrogenase in cell-free extracts.	spirillum lipoferum, an n2-fixing organism, was grown at constant concentrations of dissolved o2. when supplied with nh4+ aerobically, its doubling time was 1 h; when it fixed n2 microaerophilically, its doubling time was 5-5 to 7 h and the optimal po2 for growth was 0-005 to 0-007 atm. at its optimal po2 for growth on n2, s. lipoferum assimilated 8 to 10 mg nitrogen/g carbon substrate used; its efficiency was less at higher po2 levels. nitrogenase in cell-free extracts required mg2+ and mn2+, a ...	1977	13147
multiple low spin forms of the cytochrome c ferrihemochrome. epr spectra of various eukaryotic and prokaryotic cytochromes c.	1. despite the same methionine-sulfur:heme-iron:imidazole-nitrogen hemochrome structure observed by x-ray crystallography in four of the seven c-type eukaryotic and prokaryotic cytochromes examined, and the occurrence of the characteristic 695 nm absorption band correlated with the presence of a methionine-sulfur:heme-iron axial ligand in all seven proteins, they fall into two distinct classes on the basis of their epr and optical spectra. the horse, tuna, and bakers' yeast iso-1 cytochromes c ...	1977	13072
fermentation of pyruvate by 7 species of phototrophic purple bacteria.	the dark, anaerobic fermentation of pyruvate under growth conditions was examined with the following species of phototrophic purple bacteria: rhodospirillum rubrum strains ha and s1, rhodopseudomonas gelatinosa strain 2150, rhodopseudomonas acidophila strain 7050, rhodopseudomonas palustris strain atcc 17001, rhodopseudomonas capsulata strains kb1 and 6950, rhodopseudomonas sphaeroides strain atcc 17023, and chromatium vinosum strain d. fermentation balances were established for all experiments. ...	1976	12621
photoinactivation of photophosphorylation and dark atpase in rhodospirillum rubrum chromatophores.	preillumination of rhodospirillum rubrum chromatophores with strong, far-red light in the presence of phenazine methosulfate under non-phosphorylation conditions results in a selective, irreversible inactivation (typically about 70%) of photophosphorylation and of uncoupler-stimulated dark atpase. the time course of the photoinactivation is similar to the light-on kinetics of the light-induced proton uptake in the absence of adp. only little photoinactivation occurs when the uncoupler carbonyl c ...	1976	11818
phosphate binding to chromatophores of rhodospirillum rubrum.	equilibrium dialysis has been used to determine the binding of phosphate to chromatophores of rhodospirillum rubrum. assuming a complete exchange of the added 32pi with endogenous phosphate, the saturation with phosphate retained in any form by chromatophores was reached at about 20 nmoles pi per mg of bacteriochlorophyll. the retention of phosphate had a ph optimum at ph 6.5 to 6.8. at ph 8.0 only chromatophores which have not been liberated from dna and rna show a considerable retention of pho ...	1976	9278
effects of ph indicators on various activities of chromatophroes of rhodospirillum rubrum.	1. the effects of ph indicators on activities for atp hydrolysis in the dark and atp-pi exchange in the dark were examined with chromatophores from rhodospirillum rubrum. of thirty-one ph indicators tested, eleven (metanil yellow, 2, 4-dinitrophenol, ethyl orange, bromocresol green, resazurin, neutral red, bromthymol blue, alpha-naphtholphthalein, o-cresolphthalein, phenolphthalein, and alizarin yellow g) almost completely inhibited the activities for atp formation and atp-pi exchange at concent ...	1975	5425
d-alpha-hydroxyglutarate dehydrogenase of rhodospirillum rubrum.	d-alpha-hydroxyglutarate dehydrogenase of r. rubrum grown anaerobically in the light was partially purified and some properties were investigated. 1. the enzyme catalyze stoichiometrically the dehydrogenation reaction of d-alpha-hydroxyglutarate into alpha-oxoglutarate, coupled with the reduction of 2, 6-dichlorophenolindophenol. 2. cytochrome c2, cytochrome c, and ferricyanide are effective as electron acceptors with the crude enzyme but not with the purified one, whereas nad+ and nadp+ are com ...	1975	5424
the primary acceptor of bacterial photosynthesis: its operating midpoint potential?		1976	4013
pyruvate fermentation in rhodospirillum rubrum and after transfer from aerobic to anaerobic conditions in the dark.	the fermentative metabolism of rhodospirillum rubrum (strain ha, f1, s1) was studied after transfering the cells from aerobic to anaerobic dark culture conditions. pyruvate was metabolized mainly to acetate and formate, and to a lesser extent to co2 and priopionate, by all strains. therefore, pyruvate formate lyase would appear to be the characteristic key enzyme of the dark anaerobic fermentation metabolism in r. rubrum. strain f1 and s1 metabolized the formate further to h2 and co2. it is conc ...	1976	3145
polarographic studies on ubiquinone-10 and rhodoquinone bound with chromatophores from rhodospirillum rubrum.	redox components bound with chromatophores of rhodospirillum rubrum, and pure samples of ubiquinone-10 and rhodoquinone were studied polarographically at 24 degrees. in a mixture of ethanol and water (4 : 1, v/v) at ph 7, ubiquinone-10 and rhodoquinone had half-wave potentials (e1/2) of +43 mv and -63 mv, respectively. for both quinones, values of the electron transfer number (n) were 2 , and plots of e1/2 versus ph formed straight lines with slopes of -30 mv/ph in the neutral ph range; thus, va ...	1975	2586
oxidation-reduction properties of chromatium vinosum high potential iron-sulfur protein.	the oxidation-reduction properties of the high potential iron-sulfur protein (hipip) from chromatium vinosum have been investigated. both equilibrium and kinetic measurements demonstrate electron transport by hipip is ph independent in the ph range 7-11. the kinetics of reduction (potassium ferrocyanide, so2, s2o42-, sodium ascorbate, and rhodospirillum rubrum cytochrome c2) and oxidation (potassium ferricyanide and rhodospirillium rubrum cytochrome c2) of hipip are reported. based on the data o ...	1976	2285
alcohol dehydrogenase activity of nonsulfur purple bacteria.	rhodopseudomonas palustris, rh. viridis, rh. acidophila, and rhodomicrobium vanniellii grow on media containing ethanol, n-propanol, and n-butanol. the highest amount of lower alcohols is utilized by the strains of rh. palustris. only rh. acidophila accumulates methanol. alcohol dehydrogenase of rh. palustris, rh. viridis, and rhodospirillum rubrum requires for its activity nad, that of rhodomicrobium vanniellii--nadp, and the enzyme of rh. acidophila is active in the presence of phenazine metas ...	1975	1631