Borovsky Z, Aner R, Rottem S
Department of Membrane and Ultrastructure Research, The Hebrew University-Hadassah Medical School, P.O.B. 12272, Jerusalem 91120, Israel
Curr Microbiol. 1997 Jan;34(1):33-7. doi: 10.1007/s002849900140.
The partially purified 57-kDa protein of Spiroplasma melliferum was autophosphorylated when incubated with ATP in the presence of ZnCl2. Autophosphorylation was also apparent by showing the in situ phosphorylation of the 57-kDa protein band separated by polyacrylamide gel electrophoresis under nondenaturing conditions. The autophosphorylation was affected neither by the pH of the reaction mixture nor by the presence of NaF. The steady state level of the phosphorylated 57-kDa protein remained constant for up to 15 min, suggesting the absence of a phosphoprotein phosphatase activity in the preparation. As the initial phosphorylation rate did not decrease upon a 100-fold dilution of the 57-kDa protein under constant substrate concentration, it is suggested that the autophosphorylation is an intramolecular process.
在氯化锌存在的情况下，将蜂螺原体部分纯化的57 kDa蛋白与ATP一起孵育时，该蛋白会发生自磷酸化。通过在非变性条件下对聚丙烯酰胺凝胶电泳分离出的57 kDa蛋白条带进行原位磷酸化也可明显看出自磷酸化现象。自磷酸化既不受反应混合物pH值的影响，也不受氟化钠存在的影响。磷酸化的57 kDa蛋白的稳态水平在长达15分钟内保持恒定，这表明该制剂中不存在磷蛋白磷酸酶活性。由于在底物浓度恒定的情况下，将57 kDa蛋白稀释100倍后初始磷酸化速率并未降低，因此表明自磷酸化是一个分子内过程。
