Isolation and properties of two fragments from plasmin digests of human choriomammotropin.

Two fragments have been isolated and characterized from plasmin digests of human choriomammotropin. It was shown that these two fragments were derived from the cleavage of the Arg-Arg (positions 133-134) and the Lys-Gln (positions 140--141) bonds of the hormone: one has 133 amino acids and the other 51 amino acids. Both fragments were biologically and immunologically inactive.