The further separation of antitoxin from its associated proteins in horse serum

Abstract

The literature concerning means of purification of anti-bodies and their chemical characteristics has been thoroughly reviewed by Gibson, 1 Ledingham, 2 Banzhaf and Gibson, 3 and Brieger and Kraus. 4

Stark 5 was the first to report that by heating for one hour at 56° C, ovalbumin could be converted into a body, which, because of its precipitation and solution reactions, and also its composition, was obviously a globulin. Later Noll 6 showed the same to be true of albumin in rabbit, dog and horse serum.

My experiments were to ascertain the resulting conditions after heating antitoxic horse serum, citrated plasma, and Gibson's concentrated and partially purified antitoxic globulin solution.

An antitoxic serum by the Gibson method'gave the following: An elimination of 23 per cent. protein and an increase of antitoxic units per gram protein of 30 per cent. over the native serum. A series of the same antitoxic serum was heated for from 6 to 72 hours in closed containers, at a temperature of 57° C. After cooling to room temperature, the series was saturated with sodium chloride and brought up to a dilution of I : 10 with saturated sodium chloride solution. Twelve hours later the resulting precipitations were filtered off. Potency tests on these filtrates showed a loss of 5 per cent. after heating 6 hours and an increasing loss up to 22 per cent. after heating 72 hours. The protein converted into an insoluble condition (in saturated sodium chloride solution) was 30 per cent. for the 6-hour period, increasing up to 48 per cent. for the 72-hour period. The increase of antitoxic units, per gram protein, was 35 per cent. after 6 hours heating, increasing up to 53 per cent. after 48 hours.

Owing to the larger per cent.