Binding and activation of human plasminogen by Mycobacterium tuberculosis

The first evidence of the interaction of Mycobacterium tuberculosis with th e plasminogen system is herein reported. By FACScan analysis and affinity b lotting, lysine-dependent binding of plasminogen to M. tuberculosis was dem onstrated. The binding molecules were 30-, 60-, and 66-kDa proteins present in cell wall and soluble protein extracts. The activation of plasminogen, which occurred only in presence of fibrin and was not inhibited by the host serpin, alpha(2)-antiplasmin, was also demonstrated.