MODIFICATION OF HUMAN SERUM ALBUMIN WITH REACTIVE ALDEHYDES ALTERS THE ANTIOXIDANT ACTIVITY

摘要

Reducing sugars such as glucose non-enzymatically react with amino residues of proteins to form Schiff base and Amadori products. Further incubation converts these early products into irreversible derivatives termed advanced glycation end-products (AGEs). Protein modification by glucose results in the induction of the functional disruption of proteins such as human serum albumin (HSA), alpha-crystalline and copper-zing-superoxide dismutase. We previously reported that HSA is the major target for glycation and oxidation among plasma proteins and Miyata et al. also reported that over 90 % of N~ε-(carboxymethyl)lysine (CML) and pentosidine, well-characterized AGE structures, are generated on HSA. It is well known that HSA exhibits numerous biological functions such as maintenance of colloid osmotic pressure and transport of the endogeneous and exogenous ligands. Recent studies have focused on its antioxidant properties , and an inverse relationship between albumin level and cardiovascular diseases has been established.