Blobel C P, Myles D G, Primakoff P, White J M
Department of Biochemistry, University of California, San Francisco 94143-0450.
J Cell Biol. 1990 Jul;111(1):69-78. doi: 10.1083/jcb.111.1.69.
A protein located on the surface of guinea pig sperm (PH-30) has been implicated in the process of sperm-egg fusion (Primakoff, P., H. Hyatt, and J. Tredick-Kline. 1987. J. Cell Biol. 104:141-149). In this paper we have assessed basic biochemical properties of PH-30 and have analyzed the molecular forms of PH-30 present at different stages of sperm maturation. We show the following: (a) PH-30 is an integral membrane glycoprotein; (b) it is composed of two tightly associated and immunologically distinct subunits; (c) both subunits are made as larger precursors; (d) processing of the two subunits occurs at different developmental stages; (e) the final processing step occurs in the region of the epididymis where sperm become fertilization competent; (f) processing can be mimicked in vitro; (g) processing exposes at least two new epitopes on PH-30-one of the newly exposed epitopes is recognized by a fusion-inhibitory monoclonal antibody. These results are discussed in terms of the possible role of PH-30 in mediating fusion with the egg plasma membrane.
一种位于豚鼠精子表面的蛋白质（PH-30）被认为参与了精卵融合过程（普里马科夫，P.，H. 海亚特，和 J. 特雷迪克 - 克莱恩。1987年。《细胞生物学杂志》104:141 - 149）。在本文中，我们评估了PH-30的基本生化特性，并分析了精子成熟不同阶段存在的PH-30分子形式。我们发现如下：（a）PH-30是一种整合膜糖蛋白；（b）它由两个紧密相连且免疫特性不同的亚基组成；（c）两个亚基最初都是较大的前体；（d）两个亚基的加工在不同发育阶段发生；（e）最终加工步骤发生在附睾中精子获得受精能力的区域；（f）加工过程可以在体外模拟；（g）加工过程使PH-30上至少暴露两个新表位——其中一个新暴露的表位可被一种融合抑制性单克隆抗体识别。本文根据PH-30在介导与卵质膜融合中可能发挥的作用对这些结果进行了讨论。
