Some biological activities associated with the 10S form of human gamma-G-globulin.

Human γG-globulin fractions rich in the dimeric (10S) form have been isolated from Cohn (Squibb) preparations, by repeated gel-filtration on Sephadex G-200. These fractions have been shown to fix complement and to precipitate rhemutaoid factor, despite the absence of larger aggregates (e.g. 20–40S) with which such activities are normally associated. In contrast, native human 7S γG-globulin preparations exhibited neither activity.