Procoagulant Phospholipid Hydrolysis, Penetration Ability and Anticoagulant Activity of Phospholipases A2
Procoagulant Phospholipid Hydrolysis, Penetration Ability and Anticoagulant Activity of Phospholipases A2
复制标题
磷脂酶 A2 的促凝磷脂水解、渗透能力和抗凝活性
作者：
M. Boffa;H. Verheij;G. Haas
对.25毒液磷脂酶Az的研究证实，只有一些碱性磷脂酶Az显示出显著的抗凝血活性。它们与非抗凝血剂的区别在于它们能够渗透到磷脂酰胆碱的高度堆积的单分子膜中（1），并在没有钙的情况下与带负电荷的磷脂结合（2）。Condrea等人（3）声称抗凝活性与磷脂水解之间缺乏相关性。结果表明，黑颈猪笼草毒的碱性磷脂酶Az具有抗凝作用，但不水解血浆磷脂。我们承认这种缺乏相关性，但仅在考虑整个血浆磷脂水解时：博法（a）使用抗凝剂伯氏弧菌磷脂酶获得了类似的结果。事实上，必须指出的是，从血小板膜中产生的促凝血磷脂仅占总血浆磷脂的微量，其中磷脂酰丝氨酸（PS）起着重要作用。相反，几乎所有存在于脂蛋白中的血浆磷脂对凝血没有影响。它们基本上由磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE）组成，在薄层色谱上可见，它们代表Condrea等人测量的那些。该方法的实验限度不允许观察促凝血磷脂，尤其是PS是否水解。考虑到碱性抗凝剂磷脂酶对PS的特异性亲和力，该磷脂极有可能被非常迅速地水解。
The study of.25 venom phospholipases Az established that only some basic phospholipases Az display marked anticoagulant activity. They can be distinguished from the non anticoagulant ones by their ability to penetrate into highly-packed mono-molecular films of phosphatidylcholine (1) and to bind without calcium to negatively-charged phospholipid (2). Condrea et al (3) claimed a lack of correlation between anticoagulant activity and phospholipid hydrolysis. They showed that the basic phospholipase Az from N.nigricollis venom was anticoagulant without appreciable amount of plasma phospholipid hydrolysis. We aEee on this lack of correlation, but only when considering hydrolysis of whole plasma phospholipid: similar results were obtained by Boffa (a) using the anticoagulant V. berus phospholipase. Indeed, it has to be pointed out that procoagulant phospholipids goming from platelet membrane, represent only an insignificant amount of total plasma phospholipids and that, among them, phosphatidylserine (PS) plays the important role. In contrast, almost all plasma phospholipids present in lipoproteins, have no effect on clotting. They are composed essentially of phosphatidylcholine (PC) and phos-phatidytethanolamine (PE), visible on thin layer chromatography and they represent the ones measured by Condrea et al. The experimental limits of the method do not allow to see if procoagulant phospholipids and especially PS are hydrolyzed or not. Taking into account specific affinity of basic anticoagulant phospholipases for PS, it is highly probable that this phospholipid is very rapidly hydrolyzed.