Tung A K, Siu K P
Diabetes. 1987 Apr;36(4):491-9. doi: 10.2337/diab.36.4.491.
A large-molecular-weight proinsulin-immunoreactive protein fraction was obtained from an extract of fetal bovine pancreases by gel filtration in 6 M guanidine-1 M acetic acid. Concanavalin A-Sepharose-affinity column chromatography of the large-molecular-weight fraction yielded a discrete alpha-methyl-mannoside-displaceable immunoreactive peak that also displayed N-acetylglucosamine-specific binding to wheat germ lectin-Sepharose. Chemically tritiated and radioiodinated lectin-reactive proteins interacted specifically with antibodies to insulin and bovine proinsulin. Immunochemically purified (reaction with antibodies followed by separation of antigen-antibody complexes on protein A-Sepharose) radiolabeled lectin-reactive proteins were analyzed by gel filtration in guanidine-acetic acid and by sodium dodecyl sulfate polyacrylamide gel electrophoresis after disulfide bond-cleavage treatments. Results from these studies suggest the existence of an approximately 67,000-Mr glycoprotein that contains antigenic domains common to proinsulin and insulin.
通过在6M胍-1M乙酸中进行凝胶过滤，从胎牛胰腺提取物中获得了一种大分子量的胰岛素原免疫反应性蛋白组分。对该大分子量组分进行伴刀豆球蛋白A-琼脂糖亲和柱层析，得到一个离散的α-甲基甘露糖苷可置换的免疫反应峰，该峰也显示出与麦胚凝集素-琼脂糖的N-乙酰葡糖胺特异性结合。化学氚化和放射性碘化的凝集素反应性蛋白与胰岛素和牛胰岛素原的抗体特异性相互作用。对免疫化学纯化（与抗体反应，然后在蛋白A-琼脂糖上分离抗原-抗体复合物）的放射性标记凝集素反应性蛋白，在胍-乙酸中进行凝胶过滤分析，并在二硫键裂解处理后通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳进行分析。这些研究结果表明存在一种分子量约为67,000的糖蛋白，它含有胰岛素原和胰岛素共有的抗原结构域。
