Hayashi H, Sonobe S, Owada M K, Kakunaga T
Biochem Biophys Res Commun. 1987 Jul 31;146(2):912-9. doi: 10.1016/0006-291x(87)90617-6.
We purified three forms of 36-kDa proteins, two monomeric 36-kDa proteins, which had pIs of 7.5 (36K-I) and 6.4 (36K-II), and one 36-kDa complex (36K-C) consisting of two subunits, 36-kDa (pI 7.5) and 12-kDa (pI 5.8), from human placenta membrane. The 36-kDa subunit of 36K-C was identical to 36K-I as judged by pI, cyanogen bromide peptide mapping and immunological cross-reactivity. The three proteins showed F-actin- and phosphatidylserine-binding abilities dependent on Ca2+ concentrations at millimolar and micromolar levels, respectively. They all had phospholipase A2 inhibitory activity. Only 36K-II was phosphorylated extensively at tyrosine residue in Ca2+- and EGF- dependent manners in the membrane fraction of A431 cells. 36K-I was the best substrate for src kinase, whereas 36K-II was the best for fps kinase. However, 36K-C was not phosphorylated by any kinases used here.
我们从人胎盘膜中纯化出三种形式的36 kDa蛋白：两种单体36 kDa蛋白，其等电点分别为7.5（36K-I）和6.4（36K-II）；一种由36 kDa（等电点7.5）和12 kDa（等电点5.8）两个亚基组成的36 kDa复合物（36K-C）。根据等电点、溴化氰肽图谱分析和免疫交叉反应判断，36K-C的36 kDa亚基与36K-I相同。这三种蛋白分别在毫摩尔和微摩尔水平上表现出依赖于Ca2+浓度的F-肌动蛋白结合能力和磷脂酰丝氨酸结合能力。它们均具有磷脂酶A2抑制活性。在A431细胞的膜组分中，只有36K-II以依赖Ca2+和表皮生长因子（EGF）的方式在酪氨酸残基上被广泛磷酸化。36K-I是src激酶的最佳底物，而36K-II是fps激酶的最佳底物。然而，36K-C在此处使用的任何激酶作用下均未被磷酸化。
