Abstract
Various immunoglobulin classes have been found in the guinea pig. There are two 7S classes, denoted γ1 and γ2 (1), and a macroglobulin γM; two other classes have recently been described and are probably similar to human IgA (R. Asofsky, personal communication) and IgE (2).
Studies with γ2 and γ1 have shown the existence of two types of light chains, designated κ and γ by analogy with their human counterparts (3). No information is available on the light chains of the other classes. Peptide analysis of γ2 and γ1, their isolated chains and proteolytic fragments has indicated rather different composition of their Fc fragments but very similar Fd fragments (4).
The present report offers evidence that there are common antigenic determinants in the Fd fragments of γ2 and γ1, also shared by γM.
Materials and Methods. Normal γ2 was obtained from normal serum by precipitation with 18% Na2SO4 and chromatography on DEAE-cellulose in phosphate buffer 0.005 M, pH 8.
