Use of Oxidized Proteins in the Examination of Immunochemical Specificity in Delayed Hypersensitivity to Hapten–Protein Conjugates

Abstract

RECENT investigations of delayed hypersensitivity to hapten–protein conjugates have established clearly the importance of the carrier protein as one of the determinants of specificity^1–3. Efforts to define further such determinants are hampered to some extent by the heterogeneity of the response to immunization with a hapten–protein conjugate in which many possible antigenic determinants may play a part. In previous work⁴, it was shown that oxidation or reduction and alkylation of all disulphide bonds in several proteins (resulting in complete loss of tertiary structure with retention of primary structure) produced the most drastic reduction in the ability of these proteins to precipitate rabbit antibody and to sensitize guinea pigs to delayed hypersensitivity to the native proteins. It was thoughtthat the use of such open chains to serve as hapten carrier might provide valuable information about the relative contributions of folded structure and amino-acid sequence to the specificity involved in delayed hypersensitivity.