Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 ... | 1977 | 402366 |
| mechanisms of co2 fixation in bacterial photosynthesis studied by the carbon isotope fractionation technique. | the carbon isotope discrimination properties of a representative of each of the three types of photosynthetic bacteria chlorobium thiosulfatophilum, rhodospirillum rubrum and chromatium and of the c3-alga chlamydomonas reinhardii were determined by measuring the ratio of 13co2 to 12co2 incorporated during photoautotrophic growth. 2. chromatium and r. rubrum had isotope selection properties similar to those of c3-plants, whereas chlorobium was significantly different. 3. the results suggest that ... | 1977 | 402896 |
| isolation and characterization of an organic solvent soluble polypeptide component from photoreceptor complexes of rhodospirillum rubrum. | an organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of rhodospirillum rubrum. after extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. its isoelectric point determined by isoelectric focusing was 7.10. when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified polypeptide ran as a single band of an apparent molecular weight of 12 000. however, ... | 1977 | 402930 |
| ubiquinone and photochemical activity in rhodospirillum rubrum. | 1977 | 403533 | |
| reaction of ribulosebisphosphate carboxylase from rhodospirlilum rubrum with the potential affinity label 3-bromo-1,4-dihydroxy-2-butanone 1,4-biphosphate. | 1977 | 403917 | |
| evidence for monomeric bacteriochlorophyll in p800 of the photoreaction center from rhodospirillum rubrum. | to find out whether weak or strong coupling exists between the bacteriochlorophyll molecules of the photoreaction center, the relative efficiency of energy transfer to p870 was measured at 795 nm and at 808 nm, at room temperature and at 77 degrees k. at room temperature, both relative efficiencies are close to 100%. however, at 77 degrees k, 795 nm light has a quantum efficiency of 76% and 808 nm light has an efficiency of 87%. these results confirm the fact that p800 is formed of at least one ... | 1977 | 403944 |
| localisation of the subunits of the photosynthetic reaction centers in the chromatophore membrane of rhodospirillum rubrum. | reaction centers were isolated with the detergent lauryl dimethyl amine oxide from chromatophore membranes of rhodospirillum rubrum. the subunit composition of these reaction centers is similar to the one obtained from rhodopseudomonas spheroides: three subunits with the molecular weights of 21 000, 24 000 and 29 000. reaction centers prepared from chromatophores labeled with 131i were heavely labeled in their large subunit (h). the smaller subunits (l and m) contained only little label. sonicat ... | 1977 | 403945 |
| linear dichroism of light-induced absorbance changes of reaction centers of rhodospirillum rubrum. | 1977 | 405251 | |
| a novel pathway for l-citramalate synthesis in rhodospirillum rubrum. | when [14c]propionate was incubated with a cell-free extract of rhodospirillum rubrum in the presence of glyoxylate, atp, coa, mg2+, and mn2+, radioactivity was incorporated into mesaconate (msa) as well as into beta-methylmalate (mma) and citramalate (cma). msa was suggested to be an intermediate of the conversion of mma to cma based on the following observations. (i) when non-labeled msa was added to the cma-forming reaction system, radioactivity was trapped in msa. (ii) when msa was incubated ... | 1977 | 405381 |
| simple equipment for the growth of photosynthetic bacteria. | 1977 | 406256 | |
| purification, molecular properties, and amino acid composition of the subunits of rhodospirillum rubrum succinate dehydrogenase. | 1977 | 406851 | |
| 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. | 1977 | 408177 |
| sensitive measurement of flash induced photophosphorylation in bacterial chromatophores by firefly luciferase. | 1977 | 408188 | |
| isolation and characterization of a bacteriochlorophyll-associated chromatophore protein from rhodospirillum rubrum g-9. | 1977 | 408189 | |
| [carbonic anhydrase activity of phototropic bacteria]. | the activity of carboanhydrase was assayed in seven species of phototrophous bacteria: three species of the rhodospirillaceae genus, three species of the chromatiaceae genus, and one species of the chlorobiaceae genus. the activity of carboanhydrase was found in five species among seven. it decreased on passing from photoautotrophous to photoheterotrophous conditions of growth, and then to dark heterotrophous conditions, which correlated with the activity of the calvin cycle in the bacteria. no ... | 1977 | 408582 |
| isolation of a photosynthetic strain of rhodospirillum rubrum with an altered reaction center. | 1977 | 409348 | |
| isolation of the membrane-bound hydrogenase from rhodospirillum rubrum. | 1977 | 409403 | |
| structure and function of carotenoids in the photoreaction center from rhodospirillum rebrum. | 1977 | 409431 | |
| energy-linked nicotinamide nucleotide transhydrogenases. | 1977 | 409434 | |
| 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 ... | 1977 | 410019 |
| necessity of a membrane component for nitrogenase activity in rhodospirillum rubrum. | acetylene reduction catalyzed by nitrogenase from rhodospirillum rubrum has low activity and exhibits a lag phase. the activity can be increased by the addition of a chromatophore membrane component and the lag eliminated by preincubation with this component, which can be solubilized from chromatophores by treatment with nacl. it is both trypsin- and oxygen-sensitive. titration of the membrane component with nitrogenase and vice versa shows a saturation point. the membrane component interacts sp ... | 1977 | 410446 |
| structural aspects of the reaction center of photosynthetic bacteria calculated from triplet state zero-field splittings. | 1977 | 410658 | |
| excitation trapping by different states of photosynthetic reaction centres. | 1977 | 410664 | |
| demonstration of two 3,3'-diaminobenzidine oxidation reactions associated with photosynthetic membranes in anaerobic light-grown rhodospirillum rubrum. | photosynthetic membranes of anaerobic light-grown rhodospirillum rubrum oxidized 3,3'-diaminobenzidine. when glutaraldehyde-treated cells were exposed to 3,3'-diaminobenzidine in the light aerobically, the oxidation appeared to occur by two systems. one reaction was stimulated by white light and the second required molecular oxygen. the o2-dependent activity was inhibited by kcn. | 1977 | 410873 |
| physiological studies of spirillum lipoferum. | 1977 | 411476 | |
| the effect of electron donors and acceptors on light-induced absorbance changes and photophosphorylation in rhodospirillum rubrum chromatophores. | light-induced difference spectra between 400 and 640 nm of rhodospirillum rubrum chromatophores were performed in the presence and absence of exogenous electron donor/acceptor systems and compared with the chemical oxidation spectrum. the results indicate that the component previously defined as p430 is not a unique entity but rather represents different species, or a mixture of species, under various conditions. under all conditions in which the reaction center bacteriochlorophyll is reversibly ... | 1977 | 411652 |
| [light-induced oxygen uptake by chromatophores and subchromatophore pigment-protein complexes of rhodospirillum rubrum]. | chromatophores of r. rubrum incubated with electron donors, e. g. reduced diaminodurene, tmpd, phenazine methosulphate, cytochrome c or ferrocyanide, are able to catalyze o2 uptake upon illumination. this process is inhibited by o-phenanthroline as well as upon extraction of quinones from chromatophores, but not by antimycin a, rotenone or cn-. the o2 uptake sensitive to the action of o-phenanthroline is also observed in the illuminated subchromatophore p870 reaction center complexes and reactio ... | 1977 | 412525 |
| effects of long-term treatment with acetylene on nitrogen-fixing microorganisms. | long periods of experimental incubation with acetylene led to a multifold enhancement of acetylene-reducing activity in anabaena cylindrica, anabaenopsis circularis, rhodospirillum rubrum, and azotobacter vinelandii. rates of acetylene reduction showed a gradual increase and reached a peak after 2 to 6 h of continuous incubation under acetylene. thereafter, enzyme activity rapidly declined. a similar enhancement of ethylene production was observed when pretreatment with acetylene was interrupted ... | 1977 | 413480 |
| a comparison of electron transport and photophosphorylation systems of rhodopseudomonas capsulata and rhodospirillum rubrum. effects of antimycin a and dibromothymoquinone. | the photophosphorylation systems of rhodopseudomonas capsulata and rhodospirillum rubrum chromatophores have been compared in respect to the effects of artificial electron carriers [n-methylphenazonium methosulfate (pms) and diaminodurene], reducing agents (ascorbate in particular), and various quinones in the absence and presence of the electron transport inhibitors antimycin a and dibromothymoquinone (dbmib). in addition, the effects of both inhibitors on photosynthetic electron transport thro ... | 1978 | 414685 |
| [relation of cyclic and noncyclic electron transport in rhodospirillum rubrum chromatophores. i. experimental study of the kinetic characteristics of dark reduction of p870 with different donor concentrations in the medium]. | the kinetics of the dark recovery of photo-oxidized bacteriochlorophyll p870 was studied as a function of the intensity and duration of actinic light illumination at different concentrations of a donor in the medium. from the comparison of the experimental data with the results of mathematical modelling of the processes under investigation [1] it is concluded that electron transport is triggered for another pathway, whenever the concentration of the donor in the medium attains a certain critical ... | 1978 | 414786 |
| homoserine dehydrogenase of rhodospirillum rubrum. physical and chemical characterization. | a detailed physicochemical characterization of purified homoserine dehydrogenase of rhodospirillum rubrum is presented. the enzyme has a molecular weight of 110000 and consists of two subunits of identical molecular weight of 55000. depending on the ionic strength and protein concentration it is possible for the native enzyme to dimerize to produce an enzymatically active species of molecular weight 220000. titrations of the native and detergent-treated enzyme with a variety of sulfhydryl reagen ... | 1978 | 414912 |
| continuous monitoring of the electrical potential across energy-transducing membranes using ion-selective electrodes. application to submitochondrial particles and chromatophores. | 1978 | 414935 | |
| measurement by a flow dialysis technique of the steady-state proton-motive force in chromatophores from rhodospirillum rubrum. comparison with phosphorylation potential. | 1. in the light a transmembrane electrical potential of 100 mv has been estimated to occur in chromatophores from rhodospirillum rubrum. the potential was determined by measuring the steady-state distribution of the permeant scn- across the chromatophore membrane using a flow dialysis technique. the potential was not observed in the dark, nor in the presence of antimycin. it was dissipated on the addition of carbonyl cyanide p-trifluoromethoxyphenylhydrazone. the potential was reduced by between ... | 1978 | 416847 |
| biochemical identification of a tryptophan auxotroph in rhodospirillum rubrum. | a tryptophan auxotroph of aerobically grown rodospirillum rubrum was isolated after mutagenesis and replica plating. the mutant grows on tryptophan or indole, accumulates indole glycerol phosphate, lacks the capacity to convert indole glycerol phosphate to indole glycerol phosphate to indole, and finally is defective in photosynthetic growth. the strain is, therefore, analogous to a trp a mutant which is defective in the alpha-subunit structural gene of tryptophan synthetase. | 1978 | 417790 |
| [intermediate states formed during discharge separation in the reaction centers of rhodospirillum rubrum in the presence of a low-redox potential]. | the intermediate short-lived states arising in reaction centre preparations (rc) of purple bacterium rhodospirillum rubrum are investigated under the conditions of low redox potential. excitation by 353 and 530 nm laser pulses produced two states characterized by optical absorption changes in the range of 350--650 nm and lifetimes: 10--30 ns for the first state and 2.5 +/- 0.5 microseconds for the second one. the first state is similar to the state pf, described previously by parson et al. for r ... | 1978 | 418326 |
| bacteriochlorophyll-protein complexes from the light-harvesting antenna of photosynthetic bacteria. | 1978 | 418797 | |
| modification of rhodospirillum rubrum ribulose bisphosphate carboxylase with pyridoxal phosphate. 2. stoichiometry and kinetics of inactivation. | rhodospirillum rubrum ribulose bisphosphate carboxylase contains two high affinity binding sites for pyridoxal phosphate and two catalytic sites per dimer. however, pyridoxal phosphate binding at only one site is sufficient for inactivation of both catalytic sites. in the presence of 20 mm bicarbonate, 10 mm magnesium, and pyridoxal phosphate, the rates of inactivation and schiff base formation are pseudo-first-order and show saturation kinetics. these observations provide additional evidence th ... | 1978 | 418800 |
| the photoproduction of h2 and nh4 fixed from n2 by a derepressed mutant of rhodospirillum rubrum. | a mutant of rhodospirillum rubrum has been isolated, after mutagenesis with nitrosoguanidine, which is characterized by its inability to grow in the light on malate-minimal media with exogenous ammonia or alanine, poor growth on glutamine and vigorous growth on glutamate. this mutant produces low levels of a key nh+4 assimilation enzyme, glutamate synthase (nadph-dependent). it also exhibits significant derepression of nitrogenase biosynthesis in the presence of ammonia or alanine, being 15% der ... | 1978 | 418808 |
| proteins exposed at the surface of chromatophores of rhodospirillum rubrum: the orientation of isolated chromatophores. | the exposure of proteins at the surface of isolated chromatophores (i.e., the cytoplasmic face of intracytoplasmic membranes) of rhodospirillum rubrum was studied by proteolysis as well as by enzymatic iodination with 125i. analyses were performed after polyacrylamide gel electrophoresis of chromatophore proteins solubilized with sodium dodecyl sulfate. reversible light induced proton uptake by partially digested chromatophores was used as a criterion for the integrity of the permeability barrie ... | 1978 | 418810 |
| [effect of formate on the respiration of different microorganisms]. | the cells of methylotrophic bacteria (achromobacter parvulus 1, pseudomonas methylica 2 and 20, ps. fluorescens 45, ps. oleovorans 52) and candida methylica 101 grown in a medium with methanol take up oxygen in the presence of formiate. a. parvulus is most resistant to formiate (km = 2.3 +/- 0.5) x 10(-3) m; ki = 4 x 10(-1) m). when grown on cn substrates, these microorganisms cannot oxidize formiate (with an exception of a. parvulus). formiate also serves as a respiration substrate for e. coli ... | 1979 | 481274 |
| biological activities of lipopolysaccharides and lipid a from rhodospirillaceae. | the lipopolysaccharides and free lipid a from several strains of rhodospirillaceae were assayed comparatively with those of enterobacteriaceae in a number of biological tests. free lipid a's from rhodopseudomonas gelatinosa and rhodospirillum tenue exhibited strong serological cross-reactions with each other and with free lipid a from salmonella. lipid a's from rhodopseudomonas viridis and rhodopseudomonas palustris, although cross-reacting with each other, did not do so with either the lipid a ... | 1977 | 558961 |
| direct measurement of pure absorbance spectra of living phototrophic microorganisms. | the pure absorbance of turbid cell suspensions of various phototrophic microorganisms were determined by collecting the scattered light. a conventional spectrophotometer was used, equipped with an intergrating sphere as receiver unit, which allowed precise measurements of the absorbance in the range from zero to 0.1. in the wavelength range 300--1100 nm, where photosynthesis occurs, light scattered only once by a bacterial cell retains predominantly the forward direction. this allows measurement ... | 1978 | 626755 |
| quantum yield and image contrast of bacteriochlorophyll monolayers in photoelectron microscopy. | the photoelectron quantum yield spectrum of bacteriochlorophyll agg (bchl a ) from rhodospirillum rubrum was determined in order to evaluate the possibility of mapping photoreceptor distribution and organization in bacterial chromatophores. the quantum yield is on the order of 1 x 10(-3) electrons/incident photon at 180 nm and decreases to 2.5 x 10(-5) electrons/incident photon at 230 nm. photoelectron micrographs confirm the high contrast predicted between monolayers of bchl a against a lipid b ... | 1978 | 630040 |
| structural studies on the d-arabinose-containing lipid a from rhodospirillum tenue 2761. | structural studies carried out on the isolated free lipid a of rhodospirillum tenue 2761 revealed a new type of structure for this lipid. the lipid a backbone of 1',6-linked glucosamine disaccharide (central disaccharide) is substituted by three different sugar residues: the non-reducing end of the disaccharide by 4-amino-4-deoxy-l-arabinose 1-phosphate and its reducing end glycosidically by d-arabinofuranose 1-phosphate; further, the reducing glucosamine of the disaccharide is branched to a thi ... | 1978 | 639795 |
| purification of (4fe-4s)1--2--ferredoxins (high-potential iron--sulfur proteins) from bacteria. | 1978 | 713842 | |
| inactivation of ribulosebisphosphate carboxylase by modification of arginyl residues with phenylglyoxal. | phenylglyoxal rapidly and completely inactivates spinach and rhodospirillum rubrum ribulosebisphosphate carboxylases. inactivation exhibits pseudo-first-order kinetics and a reaction order of approximately one for both enzymes, suggesting that modification of a single residue per protomeric unit suffices for inactivation. loss of enzymic activity is directly proportional to incorporation of [14c]phenylglyoxal until only 30% of the initial activity remains. for both enzymes, extrapolation of inco ... | 1978 | 728421 |
| immunogenicity of methyl esters of nocardomycolic acids. | immunogenicity of methyl esters of fatty acids of nocardiae (nocardia (nocardia asteroides atcc 19247, n, brasiliensis n318 and n. caviae n231) was studied. the rabbit antisera obtained against the lipid fractions reacted in the complement fixation test (cf) and in the pash sive cutaneous anaphylaxis test (pca). the results of absorption experiments witt separated fractions of fatty acids esters indicate that the antisera showed activity againsmethyl esters of nocardomycolic acids. | 1978 | 749777 |
| dna homology studies on nocardia and rhodococcus strains. | the genetic homogeneity of nocardia amarae, nocardia autotrophica and rhodococcus strains and the relationship among these groups of microorganisms have been studied using the dna reassociation method. strains belonging to n. amarae and n. autotrophica form genetically homogeneous groups. distinct differences have been found out among rhodococcus strains. | 1978 | 749779 |
| primary structure of a high potential, four-iron-sulfur ferredoxin from the photosynthetic bacterium rhodospirillum tenue. | the amino acid sequence of a high oxidation-reduction potential iron-sulfur protein (hipip) isolated from the purple photosynthetic bacterium rhodospirillum tenue has been determined. this is the smallest of the hipip's, containing 63 residues, with only 3 residues apparently conserved in addition to the 4 cluster-binding cysteines. a minimum of four internal genetic gaps is postulated to align tenue high potential iron-sulfur protein with the previously known proteins. it is the most divergent ... | 1979 | 762147 |
| [photoinduced liberation of hydrogen by bacteria, algae and higher plants]. | 1975 | 803442 | |
| generation of electric potential by reaction center complexes from rhodospirillum rubrum. | 1975 | 803460 | |
| comparison of two ferredoxins from rhodospirillum rubrum as electron carriers for the native nitrogenase. | in coupling the reducing power of illuminated chloroplasts to the nitrogenase from photosynthetically grown rhodospirillum rubrum cells, one of the native ferredoxins. fdi, was found to be three times more effective than fdii. | 1975 | 803490 |
| [regulation of nitrogenase biosynthesis in microorganisms]. | 1975 | 803994 | |
| [action spectra of photosynthesis and liberation of hydrogen in bacteria, algae and higher plants]. | 1975 | 804393 | |
| carotenoid and merocyanine probes in chromatophore membranes. | 1975 | 804940 | |
| ribulose-1, 5-diphosphate carboxylase from rhadospirillum rubrum. | 1975 | 805893 | |
| ribulose-diphosphate carboxylase from the hydrogen bacteria and rhodospirillum rubrum. | 1975 | 805894 | |
| [change in the absorption spectra of carotenoids in dry films of rhodospirillum rubrum chromatophores in an external electric field]. | electrochromic spectra of carotenoids in dried films of chromatophores of rhodospirillum rubrum in 450-600 nm region are obtained. their good agreement with the photoinduced absorption changes of the same chromatophores under different conditions is shown. | 1975 | 807260 |
| [relation of chloroplast and chromatophore fluorescence yield to the state of the reaction centers]. | 1975 | 807465 | |
| [effect of temperature on the dark reduction of photooxidized bacteriochlorophyll p870 in rhodospirillum rubrum photosynthetic bacteria]. | 1975 | 809066 | |
| light-dependent atp formation in a non-phototrophic mutant of rhodospirillum rubrum deficient in oxygen photoreduction. | 1975 | 810144 | |
| carotenoid triplet states in reaction centers from rhodopseudomonas sphaeroides and rhodospirillum rubrum. | purified photochemical reaction centers from three strains of rhodopseudomonas sphaeroides and two of rhodospirillium rubrum were reduced with na2s2o4 so as to block their photochemical electron transfer reactions. they then were excited with flashes lasting 5-30 ns. in all cases, absorbance measurements showed that the flash caused the immediate formation of a transient state (pf) which had been detected previously in reaction centers from rps. sphaeroides strain r26. previous work has shown th ... | 1975 | 811259 |
| regulation of nitrogenase synthesis in intact cells of rhodospirillum rubrum: inactivation of nitrogen fixation by ammonia, l-glutamine and l-asparagine. | the synthesis of nitrogenase by intact cells of rhodospirillum rubrum was repressed in n-free media supplemented with l-glutamine or l-asparagine, but was unaffected by the presence of l-glutamate, l-aspartate or l-histidine. specific activities attained by cultures in supplemented media maintained under ar-co2 were 2 to 3 times higher than those in n-free medium under n2-co2. a loss in total activity occurred both in cultures growing with n2 after maximum activity had been reached, and in cultu ... | 1975 | 811763 |
| ultrastructural deformation studies on biological membranes. | the ultrastructural deformation technique has been used to study various membranes, including several claimed to show subunit structure. with localized deformation fibers ca. 100-300 a in diameter and up to 4,000 a long were found extending across the cracks parallel to the draw direction in all membranes. lipid extraction and proteolytic enzyme (papain) treatment of membranes has shown that the fibers are protein in nature. deformation of membranes while still wet showed no significant change i ... | 1975 | 813066 |
| possible role of firmly bound atp in the energy transduction of photosynthetic membranes. | chromatophores of rhodospirillum rubrum and spinach chloroplasts contain firmly bound atp that is rapidly labeled along with adp in the presence of 32pi and endogenous nucleotides. the labeling is not entirely dependent on light. in chloroplasts three types of bound atp can be defined methodologically by their extraction properties: buffer-soluble; acid-soluble; and sds-soluble or firmly bound atp. extensive washing of the chloroplasts does reduce buffer-soluble but not acid-soluble and firmly b ... | 1975 | 813067 |
| characterization of two cell-envelope fractions from chemotrophically grown rhodospirillum rubrum. | two cell-envelope fractions were isolated from chemotrophically grown cells of rhodospirillum rubrum. on the basis of electron-microscopic investigations, chemical analysis, distribution of components involved in respiration, and poly-acrylamide gel electrophoresis, the heavy fraction (rho20 = 1.246 g per cm3) was identified as cell-wall, and the light fraction (rho = 1.145 g per cm3) as cyto-plasmic-membrane fragments. electron micrographs showed cell-wall fragments as open structures while cyt ... | 1975 | 813575 |
| [reversible photooxidation of bacteriochlorophylls a and b in aqueous solutions of detergents]. | 1975 | 813982 | |
| formation of beta-methylmalate and its conversion to citramalate in rhodospirillum rubrum. | using a cell-free extract of rhodospirillum rubrum, studies were made of the condensation reaction between propionyl-coa and glyoxylate. when [14c]propionate was incubated with the extract in the presence of glyoxylate, atp, coa, mg2+, and mn2+, radioactivity was incorporated into several compounds. two of the main products were characterized as citramalate (cma) and erythro-beta-methylmalate (erythro-mma) on the basis of their behavior compared with authentic samples of cma and erythro-mma in t ... | 1975 | 814116 |
| primary reactions in photosynthesis. | 1975 | 814555 | |
| lipoic acid content of escherichia coli and other microorganisms. | a mutant strain of escherichia coli k-12 requiring lipoic acid. w1485lip 2 (atcc 25645), was used to develop a turbidimetric assay for lipoic acid and a polarographic assay based on the oxidation of pyruvate by suspensions of lipoic acid-deficient organisms. the turbidmetric assay was more sensitive with a working range equivalent to 0.2-2.0 ng of dl-alpha-lipoic acid compared with 5-50 ng for the polarographic method. the mutant responded equally to racemic mixtures of alpha-lipoic acid, beta-l ... | 1975 | 814874 |
| [theoretical study of the kinetics of dark reduction of photochemically oxidized bacteriochlorophyll in the reaction center of rhodospirillum rubrum chromatophores]. | it is shown from the results of theoretical study that the scheme involving two successive interacting components of the pool of secondary acceptors shows the biexponential character of the kinetics of dark reduction of the pigment of p870 observed in the experiment. the velocity constants of the electron transport reactions considered are evaluated. | 1976 | 814933 |
| [technique for the determination of the quantum yield of the primary process in the course of photosynthesis energy transformation. iii. experimental data obtained for different photosynthetic organisms]. | a relative method in two modifications has been developed for determination of the quantum yield of primary photosynthesis energy conversion. the purple bacteria e. chaposhnikovii and chr. minutissimum, r. rubrum chromatophores, cell extracts of e. shaposhnikovii, rps. spheroides strains ga and r-26, pigment-protein complexes from green bacterium chl. limicola and light subchloroplast particles, enriched in the photosystem i, were investigated. the quantum yields for all these objects were shown ... | 1975 | 815784 |
| unidirectional inhibition of phosphoenolpyruvate carboxykinase from rhodospirillum rubrum by atp. | the kinetic and regulatory properties of partially purified phosphoenolpyruvate (pep) carboxykinase (ec 4.1.1.3.2) from rhodospirillum rubrum were studied. the enzyme was active with guanosine- and inosinephosphates and must thus be classified as gtp (itp): oxaloacetate carboxylase (transphosphorylating.) in the direction of oxaloacetate-foramtion, the enzyme was strongly inhibited by atp (ki = 0.03 mm). itp, utp, ctp, and gtp were less inhibitory. the inhibition was competitive with respect to ... | 1976 | 816325 |
| new experimental approach to the estimation of rate of electron transfer from the primary to secondary acceptors in the photosynthetic electron transport chain of purple bacteria. | a method for calculating the rate constant (ka1a2) for the oxidation of the primary electron acceptor (a1) by the secondary one (a2) in the photosynthetic electron transport chain of purple bacteria is proposed. the method is based on the analysis of the dark recovery kinetics of reaction centre bacteriochlorophyll (p) following its oxidation by a short single laser pulse at a high oxidation-reduction potential of the medium. it is shown that in ectothiorhodospira shaposhnikovii there is little ... | 1976 | 816385 |
| properties of ribonucleic acids from photosynthetic and heterotrophic rhodospirillum rubrum. | rifampicin causes an initial rapid breakdown of about 30% of the pulse-labeled rna in both photosynthetic and heterotrophic rhodospirillum rubrum. an additional degradation of rna has been observed in the heterotrophic, but not in the photosynthetic cells at a later stage of rifampicin treatment. this secondary rna degradation is probably caused by breakdown of ribosomal rna, especially of the 23s species, as shown by polyacrylamide gel electrophoresis analyses. no qualitative difference between ... | 1976 | 816437 |
| cell-free, protein-synthesizing system of photosynthetic and heterotrophic rhodospirillum rubrum. | an active in vitro protein-synthesizing system has been developed from rhodospirillum rubrum grown under either photosynthetic or heterotrophic conditions. a protease activity has been found in both of these systems, and this activity can be readily inactivated by treating the cells with kcl and phenylmethyl sulfonylfluoride. the difference in protein-synthesizing activity between the photosynthetic and the heterotrophic systems has been tested in regard to the requirement of various chemicals a ... | 1976 | 816440 |
| a novel short-lived emission from the photosynthetic bacterium rhodospirillum rubrum. | 1976 | 816674 | |
| triplet states of carotenoids from photosynthetic bacteria studied by nanosecond ultraviolet and electron pulse irradiation. | 1976 | 817340 | |
| [phototransformations of bacteriopheophytin in reaction centers of rhodospirillum rubrum and crhomatium minutissimum]. | 1976 | 817883 | |
| [acid-soluble nucleotides of the phototrophic bacterium rhodospirillum rubrum during growth in light and in darkness]. | the content of acid-soluble nucleotides was different in the cells of non-sulphur purple bacterium rhodospirillum rubrum, growing phototrophically under anaerobic conditions and aerobically under conditions of heterotrophic nutrition. the cells of the culture growing in the darkness contained more adenylic and guanylic nucleotides, and the total of reduced and oxidized nadp. the cells of the culture growing in the light contained more fmn. the cells of the "light" and "dark" cultures contained g ... | 1975 | 818480 |
| early formation of intracytoplasmic membranes in rhodospillum rubrum. | cytoplasmic and intracytoplasmic membranes were isolated from rhodospirillum rubrum by equilibrium sucrose density gradient centrifugation. immediately after the induction of photosynthetically active intracytoplasmic membranes, bacteriochlorophyll is incorporated predominantly into the cytoplasmic membrane. with increasing pigment concentrations the newly arising intracytoplasmic membranes become sites of preferential bacteriochlorophyll incorporation. during this process the infrared absorptio ... | 1976 | 819036 |
| [purification and properties of rhodospirillum rubrum nadp-reductase]. | rhodospirillum rubrum cell extracts have active nadp-reductase capable of catalyzing the diaphorase reaction in the presence of methyl viologene or benzyl viologene and nadph-generating system. the greater part of nadp-reductase is localized in the soluble fraction of destroyed cells (90-10(3) g; 90 min). the purified preparation of nadp-reductase was found to contain 6 proteins, 4-5 of them possessing diaphorase activity. partially purified nadp-reductase preparation with a period of half-inact ... | 1976 | 819042 |
| [reconstruction of the function of membrane potential formation by isolated pigment-protein complexes of rhodospirillum rubrum]. | the pigment-protein complexes, containing the photosynthetic reaction centers and chlorophyll antenna, were isolated from non-sulfur purple bacteria rhodospirillum rubrum, by use of cholate. absorption spectra and quantum yield of photo-oxidation of bacteriochlorophyll p870 of complexes were similar to those of chromatophores. the procedure of reconstitution of proteoliposomes from phospholipids and complexes was proposed. the proteoliposomes incubated with coq6 and tmpd upon illumination are ge ... | 1976 | 819043 |
| motility in normal and filamentous forms of rhodospirillum rubrum. | by suitable choice of medium, rhodospirillum rubrum has been grown both in normal (length 2 mum) and filamentous (length up to 60 mum) forms. both forms were highly motile, and negatively-stained preparations showed bipolar flagellated cells, with an average of seven flagella at each pole. motion consisted of a series of runs and tumbles, the ditribution of run time-lengths being poissonian. both forms tumbled in response to dark shock and showed negative chemotaxis to oxygen. the observation th ... | 1976 | 819618 |
| phototactic response of aerobically cultivated rhodospirillum rubrum. | motile cells of aerobically cultivated rhodospirillum rubrum, containing no detectable bacteriochlorophyll, assembled at a spot of strong light projected through a dark-field condenser. far-red light was not effective, indicating that bacteriochlorophyll and thus photosynthetic metabolism was not responsible for the phenomenon. bacteria moving towards the centre of the light spot changed direction less frequently than those moving towards the margin. they also responded to temporal changes in th ... | 1976 | 819621 |
| measurement of transmembrane potentials in rhodospirillum rubrum chromatophores with an oxacarbocyanine dye. | the fluorescent dye 3,3-dipentyloxacarbocyanine (occ) can be used as a fluorescence probe to measure transmembrane potentials across rhodospirillum rubrum chromatophore membranes. a reversible fluorescence increase is observed in the light which is sensitive to inhibitors, permeable ions and uncouplers. partial interchangeability between the electrical potential and the proton concentration gradient has been demonstrated by measurement of the fluorescence increase with occ and the fluorescence q ... | 1976 | 820380 |
| membranes of rhodospirillum rubrum: isolation and physicochemical properties of membranes from aerobically grown cells. | highly purified preparations of cytoplasmic and outer membrane were isolated from aerobically grown rhodospirillum rubrum lysed by sequential treatment with lysozyme, ethylenediaminetetraacetate, and brij 58. the membranes were resolved and separated from other cellular constitutents by a combination of velocity and isopyknic sedimentation in sucrose density gradients. on the basis of their appearance in electron micrographs and their protein profiles in sodium dodecyl sulfate-polyacrylamide gel ... | 1976 | 820689 |
| membranes of rhodospirillum rubrum: physicochemical properties of chromatophore fractions isolated from osmotically and mechanically disrupted cells. | isolation of highly purified membrane fractions from phototrophically grown rhodospirillum rubrum was achieved by velocity and isopyknic sedimentation under carefully controlled ionic conditions. bacteriochlorophyll-rich and succinic dehydrogenase-rich chromatophores that were essentially devoid of contamination by non-chromatophore protein were separated from a denser fraction in extracts disrupted in a french pressure cell. highly purified chromatophores and a nearly photopigment-free envelope ... | 1976 | 820690 |
| novel nucleotides from e. coli isolated and partially characterized. | 1976 | 821487 | |
| effects of 4-[beta-(diethylamino)-ethoxy]-benzophenone upon carotenogenesis in rhodospirillum rubrum. | carotenoid production was determined in illuminated anaerobically maintained cultures of rhodospirillum rubrum in media with and without 4-[beta-(diethylamino)-ethoxy]-benzophenone. in treated cultures, lycopene--which normally is not produced by r. rubrum--accumulated as the predominant pigment, and total carotenoids increased five- to sixfold. | 1976 | 821916 |
| structural order in chromatophore membranes of rhodospirillum rubrum. | 1976 | 822349 | |
| a possible physiological function of the oxygen-photoreducing system of rhodospirillum rubrum. | anaerobic suspensions of rhodospirillum rubrum cells which had been grown in the dark under low oxygen tension showed only a small increase of their atp content when illuminated for 30 s. the same suspensions failed to start immediate growth in the light. both high light-induced atp levels and immediate phototrophic growth were elicited by small amounts of oxygen which were insufficient by themselves to raise the atp levels or to support growth in the dark. the oxygen requirement for growth disa ... | 1976 | 822793 |
| photodichroic studies of the photoreaction center from rhodospirillum rubrum. i. attribution of p870 to two non parallel dipoles. | a randomly oriented sample of photoreaction center prepared from rhodospirillum rubrum was excited at 77 degrees k by an actinic linearly polarized light of 870 nm. under such conditions, only those chromophores with components of their absorption dipoles oriented parallel to the polarization of the actinic light are bleached. the change in absorbance at 900 nm of this photoselected sample was observed while varying the angle of polarization of a weak measuring light. the polarization of the abs ... | 1976 | 822873 |
| photosynthetic regeneration of atp using bacterial chromatophores. | we have demonstrated the use of bacterial chromatophores for the continuous photosynthetic regeneration of atp from adp in an ultrafiltration reactor. biphasic kinetics of the degradation of chromatophore activity are described. using chromatophores in combination with the enzyme adenylate kinase, we have also demonstrated continuous regeneration of atp from amp. | 1976 | 822897 |
| preparation and properties of bacterial chromatophores entrapped in polyacrylamide. | the immobilization of rhodospirillum rubrum chromatophores was successfully performed by entrapping them in polyacrylamide. their photophosphorylating activity was about 40% of native chromatophores. the temperature and ph optima for immobilized chromatophores were similar to the native photosynthetic apparatus and kinetic parameters showed that the rate of photophosphorylation in polyacrylamide particles was diffusion controlled. light penetration of the gel particles was not a limiting paramet ... | 1976 | 822898 |
| inhibition of d-ribulose 1,5-bisphosphate carboxylase by pyridoxal 5'-phosphate. | 1976 | 823940 | |
| triplet states of bacteriochlorophyll and carotenoids in chromatophores of photosynthetic bacteria. | chromatophores from photosynthetic bacteria were excited with flashes lasting approx. 15 ns. transient optical absorbance changes not associated with the photochemical electron-transfer reactions were interpreted as reflecting the conversion of bacteriochlorophyll or carotenoids into triplet states. triplet states of various carotenoids were detected in five strains of bacteria; triplet states of bacteriochlorophyll, in two strains that lack carotenoids. triplet states of antenna pigments could ... | 1976 | 823977 |
| functional and structural differences between photosynthetic and heterotrophic rhodospirillum rubrum ribosomes and s-100 fractions. | cell-free, protein-synthesizing activity has been tested by using various combinations of the s-100 and ribosome fractions prepared from photosynthetic and heterotrophic rhodospirillum rubrum. the photosynthetic ribosomes are highly active when combined with either the photosynthetic or the heterotrophic s-100 fractions, whereas the heterotrophic ribosomes are active only when combined with the photosynthetic s-100 fraction. addition of a photosynthetic pigment-containing fraction to the homolog ... | 1976 | 824038 |
| activating factor for the iron protein of nitrogenase from rhodospirillum rubrum. | as isolated from rhodospirillum rubrum, the iron protein of nitrogenase has little or no activity. it can be activated by incubating it with a trypsin-sensitive, oxygen-labile component (activating factor) plus adenosine triphosphate and a divalent metal ion. after activation, the iron protein retains its nitrogenase activity when the activating factor is removed. | 1976 | 824729 |
| reconstitution of biological molecular generators of electric current. bacteriochlorophyll and plant chlorophyll complexes. | 1. electric generation by bacteriochlorophyll reaction center complexes from rhodospirillum rubrum and by photosystem i complexes from pea chloroplasts has been studied. 2. the methods for the proteoliposome reconstitution from azolectin and bacteriochlorophyll- or plant chlorophyll-containing protein complexes have been elaborated. light-dependent electric responses of the proteoliposomes were detected using (a) phenyldicarbaundecarborane anion (pcb-) probe and (b) direct measurement by a voltm ... | 1976 | 825514 |