Trypsin inhibiting material from Ascaris lumbricoides var. suum. I. Preparation of pure trypsin inhibitors

The purification of a trypsin inhibitor from Ascaris lumbricoides var. suum is described. The electrophoretically pure preparation which inhibits trypsin in a specific manner is a relatively small peptide containing 5 Asp, 4 Thr, 1 Ser, 11 Glu, 6 Pro, 6 Gly, 5 Ala, 2 Val, 10 (Cys)_1/2, 3 Ile, 2 Phe, 7 Lys, 3 Arg and 1 Try.