NATURALLY-OCCURRING ANTIBODIES REACTING WITH LIPOIC ACID - SCREENING METHOD, CHARACTERIZATION AND BIOCHEMICAL INTEREST

The development of a covalent enzyme-linked immunoassay (CELLA) using lipoic acid covalently bound to modified polystyrene microplates has p ermitted the detection, in the sera of normal BALB/c mice, of natural antibodies reacting with lipoic acid (LA). Hybridomas producing monocl onal anti-LA antibodies were obtained from splenocytes of non-immune B ALB/c mice. Two of them, of IgM isotype, recognized LA but failed to r eact with dihydrolipoic acid (DHLA, the reduced form of LA), suggestin g that the integrity of the dithiolane ring was of importance for anti body recognition. They did not give positive reactions with other disu lfide linked biological molecules such as oxidized glutathione or cyst ine. Anti-LA antibodies, coated on polystyrene microplates, were used for the detection of free LA in a competitive assay based on peroxidas e-LA conjugate.