Purification and Characterization of Two Proteins from Culture Filtrates of Mycobacterium tuberculosis H 37 Ra Strain

Abstract

Two proteins have been purified from culture filtrates of Mycobacterium tuberculosis , H 37 Ra strain by a procedure combining gel filtration, diethylaminoethyl (DEAE)-cellulose chromatography, and zone electrophoresis. The two proteins are similar in molecular weight but differ slightly in charge. The faster migrating protein, designated a 1 , is not antigenic. The slower migrating protein, designated a 2 , is antigenic both with respect to antisera and as a skin-testing antigen.