Electro-titration curves of gammaglobulin

Abstract

Three electrotitration curves of pathologic human gamma globulin have been studied, obtained by precipitation with sodium hyposulfite and electrophoretic control. A normal gam­ ma globulin curve obtained by alcoholic fractioning, and ano- ther from gamma globulin obtained from the horse by precipi­ tation with sodium hyposulfite have also been studied.

These curves have been developed in radio potenciometers and glass electrode, titrating with NaOH and C1H 0,01 N ; and have been started taking as 0, pH. 6,43 and 6,93 corresponding to the dilutions of these globulins in normal saline solution.

In all of them a point of inflection insinuates around pH. 6, which can be interpretated as the end of the titration of the carboxilic groups, and others around pH 9 to 9,5 which probably correspond to the ammonium groups of histidine and to those in the alpha position.

In the alcaline zone all the curves are very similar, while in the acid zone they present clear differences as to the intensity of decline, although, for the time being, it can not be de- termined if they are due to the pathologic nature of these gam­ ma globulins or to differences not observed in -the conditions of their obtainance or of dialysis of the same.