Rapid and large scale isolation of chymosin (rennin) by pepstatin-aminohexylagarose

A rapid and large scale isolation of chymosin was achieved by an affinity column including pepstatin-aminohexylagarose with a column of DEAE-cellulose. The affinity column with 3 ml wet gel made it possible to isolate 90 mg pure chymosins (I, II and III) from 20 g crude rennet tablet. Isoelectric points of chymosin-I, -II and -III were 4.6, 4.6 and 4.5, respectively. Each of chymosins was homogeneous electrophoretically and chromatographically.