Purification and Characterisation of Different Active Forms of Pork Trypsin

1 Pork trypsin has been separated into several active forms by chromatography on sulphoethyl-Sephadex. 2 Two of these forms have been characterised by end-group determinations as a single chain form (the β-form) and a form (the α-form) with a single internal split in its peptide chain between a lysine and a serine residue. 3 The two peptide chains of the α-form have been separated by gel electrophoresis in the presence of sodium dodecylsulphate under reducing conditions and their molecular weights appear to be approximately 11000 and 13000. 4 At a substrate concentration of 0.56 mM the β-form is 25% more active than the α-form against α-N-benzoyl-dl-arginine-p-nitroanilide.