多胺和氨基糖苷类对人羊膜磷脂酰肌醇特异性磷脂酶C的影响。

The effects of polyamines and aminoglycosides on phosphatidylinositol-specific phospholipase C from human amnion.

作者信息

Sagawa N, Bleasdale J E, Di Renzo G C

出版信息

Biochim Biophys Acta. 1983 Jun 16;752(1):153-61. doi: 10.1016/0005-2760(83)90243-6.

Abstract

The effects of polyvalent cations (polyamines and aminoglycoside antibiotics) on Ca2+-dependent phosphatidylinositol-specific phospholipase C activity of human amnion tissue were examined. In the presence of 1 mM Ca2+, the hydrolysis of phosphatidylinositol (2 mM) by phospholipase C was increased greatly (240-560% of control) by spermine (0.4 mM), spermidine (1 mM), neomycin (0.1 mM), gentamicin (0.2 mM), kanamycin (0.4 mM) and streptomycin (0.8 mM). Putrescine and cadaverine (0.1-2.0 mM), however, stimulated phospholipase C activity only slightly. The effects of spermidine, spermine and gentamicin on phospholipase C activity were characterized and found to be dependent upon the concentrations of phosphatidylinositol, Ca2+ and the particular polyvalent cation. At low concentrations of phosphatidylinositol and Ca2+ the predominant effect of polyamines and aminoglycosides was to inhibit phospholipase C activity. When the concentrations of phosphatidylinositol and Ca2+ were increased, spermidine, spermine and gentamicin stimulated phospholipase C activity. In the presence of 16 mM Ca2+, however, phospholipase C activity was maximal and was unaffected by either polyamines or aminoglycosides. At all concentrations of Ca2+ examined, the maximal stimulation of phospholipase C activity by a given polyvalent cation occurred at a fixed molar ratio of the particular polyvalent cation to phosphatidylinositol. Polyamines and aminoglycosides appeared to modulate the Ca2+ requirement for phospholipase C activity, but could not substitute completely for Ca2+. The activities of phospholipase A2, diacylglycerol lipase, monoacylglycerol lipase and diacylglycerol kinase in amnion tissue were unaffected by any of the polyvalent cations examined. It is proposed that any in vivo influences (stimulatory or inhibitory) of polyamines and aminoglycosides on amnion phospholipase C activity would depend upon the effective concentrations of Ca2+ and phosphatidylinositol.

摘要

研究了多价阳离子（多胺和氨基糖苷类抗生素）对人羊膜组织中Ca2+依赖性磷脂酰肌醇特异性磷脂酶C活性的影响。在存在1 mM Ca2+的情况下，精胺（0.4 mM）、亚精胺（1 mM）、新霉素（0.1 mM）、庆大霉素（0.2 mM）、卡那霉素（0.4 mM）和链霉素（0.8 mM）可使磷脂酶C对磷脂酰肌醇（2 mM）的水解作用大幅增加（为对照的240 - 560%）。然而，腐胺和尸胺（0.1 - 2.0 mM）仅轻微刺激磷脂酶C活性。对亚精胺、精胺和庆大霉素对磷脂酶C活性的影响进行了表征，发现其取决于磷脂酰肌醇、Ca2+和特定多价阳离子的浓度。在低浓度的磷脂酰肌醇和Ca2+时，多胺和氨基糖苷类的主要作用是抑制磷脂酶C活性。当磷脂酰肌醇和Ca2+的浓度增加时，亚精胺、精胺和庆大霉素刺激磷脂酶C活性。然而，在存在16 mM Ca2+时，磷脂酶C活性达到最大，且不受多胺或氨基糖苷类的影响。在所检测的所有Ca2+浓度下，给定多价阳离子对磷脂酶C活性的最大刺激作用发生在特定多价阳离子与磷脂酰肌醇的固定摩尔比时。多胺和氨基糖苷类似乎可调节磷脂酶C活性对Ca2+的需求，但不能完全替代Ca2+。羊膜组织中磷脂酶A2、二酰基甘油脂肪酶、单酰基甘油脂肪酶和二酰基甘油激酶的活性不受所检测的任何多价阳离子的影响。有人提出，多胺和氨基糖苷类对羊膜磷脂酶C活性的任何体内影响（刺激或抑制）将取决于Ca2+和磷脂酰肌醇的有效浓度。