Kay J, Dykes C W
Biochem J. 1976 Aug 1;157(2):499-502. doi: 10.1042/bj1570499.
In contrast with pepsin, pepsinogen does not bind pepstatin at pH values between 5.3 and 2.5. Pepsinogen is not retarded by pepstatin immobilized on to aminohexyl-Sepharose at pH5.3 or 4.1, whereas at pH3.0 activation takes place during the chromatography, with retardation of the resultant pepsin.