Dzandu J K, Johnson J F, Wise G E
Department of Anatomy, Texas College of Osteopathic Medicine, Fort Worth 76107.
Anal Biochem. 1988 Oct;174(1):157-67. doi: 10.1016/0003-2697(88)90531-3.
Water-soluble salts of several heavy metals were examined for their ability to stain polypeptides resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Brief gel exposure (5 min or less) to cobaltous acetate or chlorides of copper, nickel, and zinc produced negatively stained protein patterns that were qualitatively indistinguishable from those of parallel gels stained with Coomassie blue R-250. Protein patterns could be visualized less than 1 min after treatment of gels with zinc chloride; the threshold of detection was estimated at about 10-12 ng protein on standard-size slab gels. Test samples including human erythrocyte membranes, sialoglycoprotein (glycophorin) extracts, and commercial molecular weight protein standards were used to establish the scope of these stains. Protein patterns visualized by the heavy metal salts were compared and contrasted with profiles seen with three widely used silver stains. Proteins from gels treated with copper or zinc chloride could be easily recovered by simple diffusion; this makes feasible both analytical and preparative electrophoretic applications of the staining procedure. A mechanism is proposed to explain the observed protein staining by heavy metal salts.
研究了几种重金属的水溶性盐对十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离出的多肽进行染色的能力。将凝胶短暂暴露（5分钟或更短时间）于醋酸钴或铜、镍和锌的氯化物中，会产生负染的蛋白质条带模式，从定性角度看，与用考马斯亮蓝R-250染色的平行凝胶的条带模式没有区别。用氯化锌处理凝胶后不到1分钟就能看到蛋白质条带模式；在标准尺寸的平板凝胶上，检测阈值估计约为10-12纳克蛋白质。使用包括人红细胞膜、唾液糖蛋白（血型糖蛋白）提取物和商业分子量蛋白质标准品在内的测试样品来确定这些染色剂的适用范围。将重金属盐染色可视化的蛋白质条带模式与三种广泛使用的银染法所呈现的图谱进行了比较和对比。用氯化铜或氯化锌处理过的凝胶中的蛋白质可以通过简单扩散轻松回收；这使得该染色程序在分析和制备电泳应用中都切实可行。本文提出了一种机制来解释所观察到的重金属盐对蛋白质的染色现象。
