Interaction of heavy and light chains of myeloma immunoglobulin with pooled normal chains: quantitative analysis of association and restoration of idiotype.

We have analyzed in vitro recombinants between the isolated heavy (H) or light (L) chains of mouse myeloma protein MOPC-21 and L or H chains of normal mouse serum immunoglobulin (Ig). In the first series of experiments using fixed H chain and solubilized L chain, we have found out that only about 30% of normal L chain pool interact efficiently with individual H chain. Moreover, fractions with different affinity to H-MOPC-21 appeared to exist among normal L chains. In the second set of experiments recombination of H and L chains in solution was used. Examination of recombinants between myeloma H chain and normal L chains revealed a set representing 6% of L chain repertoire capable of forming MOPC-21-like idiotypic structure.