FIGURE 3.

Autolytic cleavage. A, Coomassie Blue-stained, self-incubated wild type and A216G guinea pig chymase after nonreducing SDS-PAGE. The uncleaved parent band is at ∼28 kDa. N termini within the 13–14 kDa bands generated by autolytic hydrolysis of wild type guinea pig chymase, as identified by Edman sequencing, are shown to the left. Elution positions of marker proteins are shown to the right. B demonstrates that cleavage sites reside in the surface-exposed 120s loop, which also contains the major site of autolytic hydrolysis in human chymase, which, however, hydrolyzes after Phe, not Leu. The arrows identify sites of hydrolysis.