非洲爪蟾卵母细胞膜中存在的磷脂酶C的特性。磷脂酸的刺激作用。

Characteristics of phospholipase C present in membranes of Xenopus laevis oocytes. Stimulation by phosphatidic acid.

Jacob G, Allende C C, Allende J E

Departamento de Bioquímica, Facultad de Medicina, Universidad de Chile, Santiago.

Comp Biochem Physiol B. 1993 Dec;106(4):895-900. doi: 10.1016/0305-0491(93)90047-9.

Abstract

Phospholipase C activity present in the membranes of Xenopus laevis oocytes has been studied. 2. These membranes contain an activity capable of hydrolyzing phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. 3. Hydrolysis of PtdIns 4,5-P2 is absolutely dependent on the presence of Ca2+, however, the hydrolysis of PtdIns occurs in the absence of Ca2+ but addition of the cation stimulates the reaction. 4. Spermine, spermidine and polylysine cause significant stimulation of the phospholipase C activity. 5. Phosphatidic acid causes approximately a 2-fold stimulation of the hydrolysis of both PtdIns and PtdIns 4,5-P2. With PtdIns as substrate, this stimulatory effect of phosphatidic acid is specific and reaches a maximum at a 400 microM concentration.

摘要

对非洲爪蟾卵母细胞膜中存在的磷脂酶C活性进行了研究。2. 这些膜含有一种能够水解磷脂酰肌醇、磷脂酰肌醇4-磷酸和磷脂酰肌醇4,5-二磷酸的活性。3. 磷脂酰肌醇4,5-二磷酸的水解绝对依赖于Ca2+的存在，然而，磷脂酰肌醇的水解在没有Ca2+的情况下发生，但添加阳离子会刺激该反应。4. 精胺、亚精胺和聚赖氨酸会显著刺激磷脂酶C活性。5. 磷脂酸对磷脂酰肌醇和磷脂酰肌醇4,5-二磷酸的水解均产生约2倍的刺激作用。以磷脂酰肌醇为底物时，磷脂酸的这种刺激作用具有特异性，在400微摩尔浓度时达到最大值。