Zarina Arif
Aligarh Muslim University, India
Title: Peroxynitration of albumin creates binding site for autoantibodies in diabetes mellitus
Biography
Biography: Zarina Arif
Abstract
It has been suggested that stress can play a major role in the etiopathogenesis of numerous diseases including diabetes mellitus. Superoxide and nitric oxide are two such stressors produced during inflammation in high amount. They can combine to produce peroxynitrite anion (ONOO-) which is potent oxidizing and nitrating agent. Thus, its interaction with biomolecules can cause oxidation as well as nitration. In the present study, albumin was modified by peroxynitrite and structural changes have been studied by UV, fluorescence, CD and Congo red binding. Analysis of modified-albumin showed increased level of carbonyl, nitrotyrosine and dityrosine. Thiol content was significantly reduced in modified-HSA. Reduction of plasma antioxidant power has been reported in diabetes mellitus and under such conditions peroxynitrite may modify albumin. This may modify the antigenic properties of albumin. Subsequent processing of modified-albumin by immune cells may generate autoantibodies. Thus, peroxynitrite-modified-HSA was used as antigen for detecting autoantibodies in diabetes mellitus sera by ELISA. Peroxynitrite-modified-HSA was bound by the diabetic autoantibodies. The study demonstrates that peroxynitration can generate immunologically active epitope on HSA.