Effect of light on generation of colored silver colloids in protein solutions.
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.
Malygin
A G
AG
Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow, 117071, Russia. inbio@glas.apc.org
D000818:Animals; D003102:Colloids; D003116:Color; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008027:Light; D010777:Photochemistry; D011506:Proteins / Q000737:chemistry / Q000528:radiation effects*; D012834:Silver / Q000737:chemistry; D012996:Solutions
D003102:Colloids; D011506:Proteins; D012996:Solutions; D012834:Silver