@article{mbs:/content/journal/micro/10.1099/00221287-137-11-2611, author = "Romero, Irma and Gómez-Priego, Alberto and Celis, Heliodoro", title = "A membrane-bound pyrophosphatase from respiratory membranes of Rhodospirillum rubrum", journal= "Microbiology", year = "1991", volume = "137", number = "11", pages = "2611-2616", doi = "https://doi.org/10.1099/00221287-137-11-2611", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-137-11-2611", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "A pyrophosphatase activity was found in respiratory membranes of Rhodospirillum rubrum. This activity was specific for pyrophosphate and was inhibited by dicyclohexylcarbodiimide, NaF and pyrophosphate analogues, but not by oligomycin or LiCl. The divalent cation selectivity was Zn2+ > Mg2+ > Co2+ > Ca2+, and the pH dependence was the same as that of the membrane-bound pyrophosphatase of chromatophores (optimum pH 6·5). The pyrophosphate hydrolysis activity of respiratory membranes was inhibited by 1-butanol. The enzyme was solubilized by Triton X-100, and the activity of the solubilized enzyme was stimulated by phospholipids. The respiratory-membrane enzyme ran in native electrophoresis with the same R F as the membrane-bound pyrophosphatase of chromatophores. Antibodies raised against both enzymes cross-reacted with each other. These findings show that a membrane-bound pyrophosphatase is present in respiratory membranes of R. rubrum and is similar to the enzyme of photosynthetic membranes.", }