Davis J W, Moses I S, Ndubuka C, Ortiz R
Department of Biology and Medical Laboratory Technology, Bronx Community College of the City University of New York, Bronx 10453.
J Gen Microbiol. 1987 Jun;133(6):1453-9. doi: 10.1099/00221287-133-6-1453.
Cell-free extracts of Ureaplasma urealyticum strains Pi and T960 (CX8) (serovars 6 and 8, respectively) metabolized inorganic pyrophosphate (PPi). The inorganic pyrophosphatase (PPase) activity was greatest with Mg2+ as cofactor, but Mn2+ acted as a poor substitute. The PPases of the two serovars differed electrophoretically. Although the highest PPase activity was obtained using PPi as substrate, the enzyme could also utilize to a lesser degree both tripolyphosphate and trimetaphosphate. No activity was observed against beta-glycerophosphate, naphthyl phosphates, glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-bisphosphate, thiamin pyrophosphate, phosphoribosylpyrophosphate, ADP or ATP. Acid- and alkaline-phosphatase activities were observed with naphthyl phosphates as substrates, but they did not have the same electrophoretic mobility on gels as the PPase activity. U. urealyticum PPase was inhibited by oxidized glutathione, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, phenylglyoxal, p-chloromercuribenzoic acid, Mn2+, Zn2+ and Ca2+. Neither reduced glutathione, L-cysteine nor Co2+ enhanced activity. PPi can act as a substrate or regulator of certain metabolic reactions, and PPi metabolism can function in bacterial bioenergetics; its role in ureaplasmas is presently unclear.
解脲脲原体Pi株和T960（CX8）株（分别为血清型6和8）的无细胞提取物可代谢无机焦磷酸（PPi）。以Mg2+作为辅因子时，无机焦磷酸酶（PPase）活性最高，但Mn2+作为替代辅因子时活性较差。这两种血清型的PPase在电泳上存在差异。虽然以PPi作为底物时可获得最高的PPase活性，但该酶在较小程度上也可利用三聚磷酸和三偏磷酸。未观察到对β-甘油磷酸、萘基磷酸、葡萄糖6-磷酸、果糖6-磷酸、果糖1,6-二磷酸、硫胺素焦磷酸、磷酸核糖焦磷酸、ADP或ATP的活性。以萘基磷酸作为底物时可观察到酸性和碱性磷酸酶活性，但它们在凝胶上的电泳迁移率与PPase活性不同。解脲脲原体PPase受到氧化型谷胱甘肽、1-乙基-3-（3-二甲基氨基丙基）碳二亚胺、苯乙二醛、对氯汞苯甲酸、Mn2+、Zn2+和Ca2+的抑制。还原型谷胱甘肽、L-半胱氨酸和Co2+均未增强其活性。PPi可作为某些代谢反应的底物或调节剂，PPi代谢可在细菌生物能量学中发挥作用；其在脲原体中的作用目前尚不清楚。
