ζ-Crystallin, a major taxon-specific protein of the guinea pig lens, has been shown to be distantly related to the alcohol/polyol dehydrogenase family and to specifically bind NADPH. The capacity of ζ-crystallin to function catalytically was investigated in the present study. ζ-Crystallin exhibited an NADPH-dependent oxidoreductase activity with 2,6-dichlorophenolindophenol (DCIP). The NADPH:DCIP oxidoreductase activity of ζ-crystallin exhibits a linear response with increasing protein concentration, and saturation kinetics with NADPH and DCIP. This activity was abolished by heat inactivation and immunoadsorption of the protein. Dicumarol, Cibacron blue, manganese, and sulfhydryl reagents were inhibitory.
ASJC Scopus subject areas
- Molecular Biology