Breyer J A, Cohen S
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tenneesee 37232-0146.
J Biol Chem. 1990 Sep 25;265(27):16564-70.
To understand the biology and the biochemistry of the epidermal growth factor (EGF) precursor in normal tissues we partially purified the EGF precursor from mouse kidney. The precursor was purified by affinity chromatography, using wheat germ lectin and antibodies to murine EGF. The EGF precursor is a glycosylated integral membrane protein of apparent molecular mass of 140-150 kDa. The solubilized EGF precursor is biologically active as evidenced by its ability to compete with 125I-labeled EGF for binding to the EGF receptor in intact fibroblasts and its ability to stimulate the growth of cells dependent on EGF for growth. The EGF precursor from mouse kidney can be proteolytically processed by the EGF-associated arginine esterase into a smaller fragment (97 kDa) that retains both immunologic sensitivity to EGF antiserum and biological activity. Extensive digestion of the EGF precursor with pepsin liberates a biologically and immunologically active protein of approximately the size of mature EGF.
为了解正常组织中表皮生长因子（EGF）前体的生物学和生物化学特性，我们从小鼠肾脏中部分纯化了EGF前体。使用麦胚凝集素和抗鼠EGF抗体通过亲和层析法纯化该前体。EGF前体是一种糖基化的整合膜蛋白，表观分子量为140 - 150 kDa。溶解的EGF前体具有生物活性，这可通过其在完整成纤维细胞中与125I标记的EGF竞争结合EGF受体的能力以及刺激依赖EGF生长的细胞生长的能力得以证明。来自小鼠肾脏的EGF前体可被与EGF相关的精氨酸酯酶进行蛋白水解处理，形成一个较小的片段（97 kDa），该片段保留了对EGF抗血清的免疫敏感性和生物活性。用胃蛋白酶对EGF前体进行广泛消化可释放出一种生物学和免疫学活性的蛋白质，其大小约为成熟EGF的大小。
