Pepsin-catalysed transpeptidation of the amino-transfer type

Abstract

The progressive loss of activity of the enzyme pre- parations during dialysis suggested that some cofactor was being removed from the enzyme by the treatment. This was tested by adding a concentrate of the diffusate to the enzyme preparations, but no reactivation of the enzyme preparations was obtained. This suggests that, if loss of activity of the enzymes is due to a loss of a cofactor, then this cofactor must be labile under the conditions of dialysis and subsequent concentration of the aqueous diffusate.