Naubatova M K, Litvinko N M, Kisel' M A, Akhrem A A
Biokhimiia. 1992 Apr;57(4):597-603.
Phospholipase A2 hydrolysis of neutral and negatively charged lipid membranes modified by positively charged proteins has been studied using liposomes composed of either dioleoylphosphatidylcholine (DOPC) or dioleoylphosphatidylglycerol (DOPG) alone or their equimolar mixture in the presence of cytochrome c, histone H1, cytochrome b5, and polylysine. Twenty minutes after the reaction had been initiated, DOPC hydrolysis was 58%, while that in the equimolar mixture with DOPG was 35%. DOPG hydrolysis was more complete in binary mixtures of liposomes. The same was observed for liposomes in the presence of cytochrome c. Hydrolysis of phospholipids in binary liposomes in the presence of histone H1 was 3 times faster than that in protein-free liposomes. In the presence of polylysine the rate of DOPG hydrolysis was decreased. The results obtained are suggestive of electrostatic interactions between hydrophilic proteins and negatively charged phospholipids, the phospholipase A2 catalytic activity being affected by these interactions.
利用由二油酰磷脂酰胆碱（DOPC）或二油酰磷脂酰甘油（DOPG）单独组成或其等摩尔混合物形成的脂质体，在细胞色素c、组蛋白H1、细胞色素b5和聚赖氨酸存在的情况下，研究了磷脂酶A2对由带正电蛋白质修饰的中性和带负电脂质膜的水解作用。反应开始20分钟后，DOPC的水解率为58%，而与DOPG的等摩尔混合物中的水解率为35%。在脂质体的二元混合物中，DOPG的水解更完全。在细胞色素c存在的情况下，脂质体也观察到同样的情况。在组蛋白H1存在的情况下，二元脂质体中磷脂的水解速度比无蛋白脂质体中的快3倍。在聚赖氨酸存在的情况下，DOPG的水解速率降低。所得结果表明亲水性蛋白质与带负电的磷脂之间存在静电相互作用，这些相互作用影响磷脂酶A2的催化活性。
