GLYCATED CU,ZN-SUPEROXIDE DISMUTASE IN RAT LENSES - EVIDENCE FOR THE PRESENCE OF FRAGMENTATION IN-VIVO

Cu,Zn-superoxide dismutase (Cu,Zn-SOD) exists in tissues of rats as bo th glycated arid non-glycated forms when separated by boronate acid co lumn chromatography. Glycated Cu,Zn-SOD is most abundant in rat lenses compared to other tissues. In normal rats lens levels of glycated Cu, Zn-SOD showed a gradual increase with age, whereas in diabetic rats su bstantial increases were observed. Immunoblotting analyses, using anti -hexitol lysine IgG, indicated that glycated Cu,Zn-SOD contains Amador i products. Moreover, Cu,Zn-SOD in lenses was site-specifically fragme nted probably because of glycation. This is the first report of a frag mented protein, such as Cu,Zn-SOD, occuring in vivo. (C) 1996 Academic Press, Inc.