Association of phospholipase A with a myocardial membrane preparation containing the (Na + +K + )-Mg 2+ -ATPase.
Association of phospholipase A with a myocardial membrane preparation containing the (Na + +K + )-Mg 2+ -ATPase.
复制标题
磷脂酶 A 与含有 (Na K )-Mg 2 -ATP 酶的心肌膜制剂的结合。
DOI：
10.1016/0022-2828(72)90057-0
复制
发表时间：
1972
影响因子：
5
通讯作者：
A. Stam
中科院分区：
文献类型：
--
作者：
W. Weglicki;B. M. Waite;A. Stam
用脱氧胆酸处理犬心肌匀浆，然后用碘化钠提取，制备了含有瓦阿因敏感(Na++ K+)-Mg2+- atp酶的膜。测定了磷脂酶A1、磷脂酶a2和溶血磷脂酶的活性。磷脂酶a2的最适pH为8.0，经1.0 mm-EDTA刺激。磷脂酶a1具有6.5 ~ 8.0的广泛pH活化，对Ca2+和EDTA具有不同的敏感性。溶血磷脂酶活性仅在酸性pH下存在，并受到EDTA的刺激。这些酶活性与先前报道的心肌微粒体、线粒体和溶酶体中的磷脂酶活性不同。含有(Na++ K+)-Mg2+- atp酶的膜的细胞内起源的鉴定是不确定的。然而，如果这种制剂富含肌层膜，磷脂酶的几个作用可能被假设：调节磷脂依赖酶的活性，如(Na++ K+)-Mg2+- atp酶，调节肌层通透性。
Membranes containing the ouabain-sensitive (Na++ K+)-Mg2+-ATPase were prepared by treatment of a homogenate of canine heart muscle with deoxycholate followed by extraction with sodium iodide. Phospholipase A1, phospholipase A2and lysophospholipase activities were found in this preparation of membranes. Phospholipase A2had a pH optimum of 8.0 and was stimulated by 1.0 mm-EDTA. Phospholipase A1activity had a broad pH activation from 6.5 to 8.0 and showed variable Ca2+and EDTA sensitivity. Lysophospholipase activity was present only at acid pH and was stimulated by EDTA. These enzymic activities were different from those of phospholipases previously reported in cardiac microsomes, mitochondria and lysosomes. Identification of the intracellular origin of the membranes containing the (Na++ K+)-Mg2+-ATPase is uncertain. However, if this preparation is enriched with sarcolemmal membranes, several roles for the phospholipases may be postulated: modulating the activity of phospholipid-dependent enzymes, such as the (Na++ K+)-Mg2+-ATPase, and regulating sarcolemmal permeability.