Isolation of tuberculin skin test reactive proteins from heated culture filtrate of Mycobacterium tuberculosis H37Rv.

Reactivity in the tuberculin skin test and mobility in disc gel electrophoresis were applied to the purification of the protein fractions from heated culture filtrate of Mycobacterium tuberculosis H37Rv. Five pure proteins were isolated with different relative mobilities in disc gel electrophoresis; all of the proteins were skin test reactive. Cultivation for approximately 4 weeks on Sauton medium at 37° C was preferable for obtaining the proteins without modification by autolysis. A simple purification method was devised for removing carbohydrates and nucleic acids without decreasing the potency of skin test reactivity from the preparation at the stage that corresponded to purified protein derivate. The partially purified preparation was treated further with an ion exchanger, by passage through a molecular sieve, and was finally submitted to disc gel electrophoresis on a preparative scale. The molecular weight of the isolated proteins was 10,000 and was estimated by electrophoresis in acrylamide gels wit...