7 S Globulin, Immunologically Identical to 19 S Gamma-1 (beta-2)-M-globulin, a New Protein of Horse Serum

Abstract

KLAUSNER¹ described, at the beginning of the century, a precipitation produced by distilled water in syphilitic sera. This reaction was afterwards found in kala-azar (especially by Brahmahari and later by Sia; also called the Sia test), in malaria, in Waldenstroem's macroglobulinæmia, in the syndrome called African splenomegalia and in sleeping sickness. Chorine² showed that it consists in fact in an extension of the normal euglobulin precipitation to the alkaline area. The same extension was found by Felton³ in the serum of horse immunized by pneumococci. Later it was demonstrated that this is the case for all horses immunized intravenously with bacteria. We show here that in equine serum the fraction responsible for this alkaline precipitation is composed mainly of a 7 S globulin, immunologically identical to 19 S γ-1 ((β-2)-M-globulin.