(A) SDS/PAGE analysis of the purified 45-kDa PTTH under both nonreducing and reducing (2-mercaptoethanol) conditions. Lanes: M, molecular mass markers; 1, 1.0 μg of pure PTTH under nonreducing conditions; 2, 3.0 μg of pure PTTH under reducing conditions. To conserve space the figure was cropped and the smaller fragments—e.g., 10 kDa are not shown. (B) N-terminal amino acid sequence of two reduced PTTH fragments, A and B.