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.
Journal Article Purification and Identification of the Factor Capable of Converting Ca2+-ATPase into Mg2+-ATPase Present in Rhodospirillum rubrum Chromatophores Get access Gilbu SOE, Gilbu SOE Division of Enzymology, Institute for Protein Research, Osaka UniversitySuita, Osaka 565 Search for other works by this author on: Oxford Academic PubMed Google Scholar Nozomu NISHI, Nozomu NISHI Division of Enzymology, Institute for Protein Research, Osaka UniversitySuita, Osaka 565 Search for other works by this author on: Oxford Academic PubMed Google Scholar Tomisaburo KAKUNO, Tomisaburo KAKUNO Division of Enzymology, Institute for Protein Research, Osaka UniversitySuita, Osaka 565 Search for other works by this author on: Oxford Academic PubMed Google Scholar Jinpei YAMASHITA, Jinpei YAMASHITA Division of Enzymology, Institute for Protein Research, Osaka UniversitySuita, Osaka 565 Search for other works by this author on: Oxford Academic PubMed Google Scholar Takekazu HORIO Takekazu HORIO Division of Enzymology, Institute for Protein Research, Osaka UniversitySuita, Osaka 565 Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Biochemistry, Volume 87, Issue 2, February 1980, Pages 473–481, https://doi.org/10.1093/oxfordjournals.jbchem.a132767 Published: 01 February 1980 Article history Received: 13 July 1979 Published: 01 February 1980
An antiserum against NADH: hemeprotein oxidoreductase [EC 1.6.99.3] was obtained by injection into rabbits of the enzyme purified from extracts of whole cells of Rhodospirillum rubrum. With the use of the antiserum, the functional role of the enzyme in the electron transport system of chromatophores was studied. The activities for NADH-cytochrome c2 reduction of chromatophores and pure preparations of the enzyme were approximately 50% inhibited in the presence of the antiserum; in the case with the enzyme, approximately 50% of the enzyme formed insoluble complex with the antiserum. With chromatophores, the antiserum inhibited also the activity for succinate-NAD+ reduction driven by either ATP or light and the activity for NADH-induced photosynthetic ATP formation. To the contrary, it did not influence the activity for succinate-cytochrome c2 reduction and the activities for photosynthetic ATP formation induced by ascorbate, succinate, and phenazine metho-sulfate. On the basis of these findings, it was concluded that the chromatophore membrane contained the same NADH: hemeprotein oxidoreductase as the purified enzyme, and that the bound enzyme was functional in donation of electrons from NADH to the photosynthetic, cyclic electron transport system.
Abstract— Carotenoids extracted from the reaction center (RC), the light‐harvesting complex (LH), and the chromatophore membrane of Rhodospirillum rubrum SI were analyzed by high‐performance liquid chromatography. The chemical structures and the configurations of major components were determined by means of mass, Raman, electronic absorption and 1 H‐NMR spectroscopy. The results indicated: (1) 15‐ cis ‐spirilloxanthin is bound to RC; (2) both all‐frans‐spirilloxanthin and aII‐(ran.s‐3,4‐dihydrospirilloxanthin are bound to LH and (3) 13‐cK‐spirilloxanthin is additionally present in the chromatophore membrane. The natural selection of the carotenoid configurations, i.e. 15‐ris by RC and aW‐trans by LH, is discussed in relation to the physiological functions and the photophysical properties of isomeric carotenoids.
Colicin K greatly decreased the incorporation of 32P-labeled inorganic orthophosphate into nucleotides and nucleic acids, causing a concomitant increase in the formation of 32P-labeled sugar phosphates in sensitive cells of Escherichia coli. These sugar phosphates were formed in aerobically growing cells, as well as in cells under stringent control of ribonucleic acid synthesis. The main 32P-labeled product was identified as sedoheptulose 7-phosphate in two strains (B1 and K-12 MK-1) and fructose 1,6-diphosphate in one strain (K-12 CP78). The formation of sugar phosphates induced by colicin K was inhibited by carbonyl cyanide m-chlorophenylhydrazone. It was also not observed in N,N'-dicyclohexylcarbodiimide-treated cells or Mg2+-(Ca2+)-adenosine triphosphatase-less mutant (strain K-12 AN120) cells. Thus, the formation of sugar phosphates in colicin K-treated cells is dependent on the formation of adenosine 5'-triphosphate by oxidative phosphorylation.
