Malygin A G
Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow, 117071, Russia.
Biochemistry (Mosc). 1998 May;63(5):529-32.
The exposure to light (20 mW/cm2, an incandescence lamp) of weakly alkaline protein solutions which contained silver nitrate and formaldehyde initiated reduction of silver ions with the subsequent generation of colored silver colloids. At light intensities lower than 0.2 mW/cm2 the generation of colored silver colloids was delayed. The rate of silver reduction depended on the protein type and on the light spectral structure. In particular, solutions which contained prealbumin, lysozyme, gamma-globulin, and transferrin were more photosensitive than solutions which contained albumin, pepsin, and beta-amylase. The formation of [Ag(NH3)2]+ complex after an addition of ammonium ions into the solutions preferentially suppressed silver reduction in the dark and under exposure to red light, thus resulting in a significant difference in the time of appearance of colored silver colloids when the solutions were exposed to violet or red light. These findings are promising for the elaboration of selective silver development of proteins in polyacrylamide gels.
含有硝酸银和甲醛的弱碱性蛋白质溶液在光照（20毫瓦/平方厘米，白炽灯）下会引发银离子的还原，随后生成有色银胶体。在光强低于0.2毫瓦/平方厘米时，有色银胶体的生成会延迟。银还原的速率取决于蛋白质类型和光谱结构。特别地，含有前白蛋白、溶菌酶、γ-球蛋白和转铁蛋白的溶液比含有白蛋白、胃蛋白酶和β-淀粉酶的溶液更具光敏性。向溶液中加入铵离子后形成的[Ag(NH3)2]+络合物优先抑制暗处和红光照射下的银还原，因此当溶液暴露于紫光或红光时，有色银胶体出现的时间会有显著差异。这些发现对于在聚丙烯酰胺凝胶中精心设计蛋白质的选择性银显影很有前景。
