The reactivity of rheumatoid factor with human gamma G globulin.

The precipitation reaction between denatured human γG globulin and rheumatoid arthritic serum has been employed in quantitative form to provide further indication of the antibody nature of rheumatoid factor. In addition, ultracentrifugal and optical rotation studies have revealed that the degree of reactivity of the γG globulin in such a system depends on its extent of denaturation irrespective of the type of denaturing agent (heat, alkali, detergent) employed. Evidence is presented to suggest that denaturation processes responsible for effecting the precipitation reactivity of human γG globulin (with rheumatoid factor) bring about the rupture of inter-chain disulphide bonds in the `fast' papain digestion (i.e. Fc) parts of the molecules and these take part in intermolecular bridging, leading to aggregate formation and probably to the exposure of new chemical groupings.