Moore A, Ensrud K M, White T W, Frethem C D, Hamilton D W
Department of Cell Biology and Neuroanatomy, University of Minnesota, Minneapolis.
Mol Reprod Dev. 1994 Feb;37(2):181-94. doi: 10.1002/mrd.1080370209.
Monoclonal antibody 4E9, which was raised against a partially purified detergent extract of rat caudal epididymal sperm, recognizes the tail of sperm from the cauda, but not from caput epididymidis, as well as epithelial cells in a restricted region of the distal caput/corpus epididymidis and proteins in epididymal fluid from corpus and cauda epididymidis. The antigen is apparently a glycoprotein, since it is retained on a Ricinus communis agglutinin I lectin column. Epididymal fluid antigens have apparent M(rs) of 38-26 kD, whereas the membrane-associated form of the molecule has an M(r) of 26 kD. Immunocytochemical data and Western immunoblot data suggest that the membrane antigen is derived from the fluid antigen, which, in turn, is secreted by the epididymal epithelium. Characterization of the membrane antigen indicates that it is tightly associated with the sperm surface, behaving as though it is an integral membrane protein. The antigen persists on ejaculated sperm.
单克隆抗体4E9是通过大鼠附睾尾精子的部分纯化去污剂提取物制备的，它能识别附睾尾精子的尾部，但不能识别附睾头精子的尾部，还能识别附睾头远端/附睾体有限区域的上皮细胞以及附睾体和附睾尾的附睾液中的蛋白质。该抗原显然是一种糖蛋白，因为它能保留在蓖麻凝集素I凝集素柱上。附睾液抗原的表观分子量为38 - 26kD，而该分子的膜相关形式的分子量为26kD。免疫细胞化学数据和Western免疫印迹数据表明，膜抗原来源于液体抗原，而液体抗原又是由附睾上皮分泌的。膜抗原的特性表明它与精子表面紧密结合，表现得好像是一种整合膜蛋白。该抗原在射出的精子上持续存在。
