Purification and Antigenic Specificity of Alpha Protein (Yoneda and Fukui) from Mycobacterium tuberculosis and Mycobacterium intracellulare

Alpha protein antigen isolated from culture filtrate of Mycobacterium tuberculosis by Yoneda and Fukui (1961) was a cross-reacting material among mycobacteria. Purified alpha protein of M. tuberculosis obtained by a series of procedures with gel filtration, ion-exchange chromatographies, and chromatofocusing. Alpha protein of Mycobacterium intracellulare was purified by an affinity chromatography on anti M. tuberculosis-alpha serum conjugated sepharose. Alpha antigen of M. tuberculosis possessed specific antigenic determinants for both M. tuberculosis and M. bovis, and so did alpha antigen of M. intracellulare for both M. intracellulare and M. avium. Extracts from M. kansasii, M. scrofulaceum, M. gordonae, M. xenopi and M. gastri showed alpha antigenicity somewhat different from those of M. tuberculosis and M. intracellulare. Alpha antigen was not detected in extracts from M. nonchromogenicum, M. terrae and M. triviale.