Phospholipase A activity associated with membranes of human polymorphonuclear leucocytes.
Phospholipase A activity associated with membranes of human polymorphonuclear leucocytes.
复制标题
与人多形核白细胞膜相关的磷脂酶 A 活性。
作者：
R. Franson;J. Weiss;L. Martín;J. Spitznagel;P. Elsbach
人多形核白细胞(粒细胞)的匀浆中含有一种依赖于钙离子的磷脂酶A，其最适活性为pH7.0。这种酶是膜结合的，富含粗细胞质颗粒部分。胞质颗粒组分的区带离心法表明，磷脂酶A不仅与特殊的和亲天青的颗粒群有关，而且还与占整个匀浆碱性磷酸酶总活性85%的空泡状组分有关。因此，这种磷脂酶与颗粒以及人粒细胞的其他细胞膜有关。
Homogenates of human polymorphonuclear leucocytes (granulocytes) contain a Ca2+-dependent phospholipase A with optimal activity pH7.0. This enzyme is membrane-bound and is enriched in crude cytoplasmic-granule fraction. Ratezonal centrifugation of the cytoplasmic-granule fraction demonstrates that the phospholipase A is associated not only with specific- and azurophilic-granule populations but also with an 'empty' vesicular fraction containing 85% of the total alkaline phosphatase activity of whole homogenate. Thus this phospholipase is associated with granule as well as with other cellular membranes of human granulocytes.