THIOPHILIC INTERACTION CHROMATOGRAPHY OF SWEET-POTATO BETA-AMYLASE

The affinity of sweet potato beta-amylase toward two kinds of thiophilic adsorbents [the so-called thiophilic or T-gel and 3-(2-pyridylsulphido)-2-hydroxypropylagarose or PyS-gel] was demonstrated. Enzyme adsorption on both gels was promoted by antichaotropic salts. Lower salt requirements and higher protein recoveries were observed for the PyS gel, even though its ligand concentration was half that of T-gel. For the former gel, the effectiveness series for sulphates was Na2SO4 > (NH4)2SO4 > K2SO4 > MgSO4. Based on the thiophilic character exhibited by the pure sweet potato beta-amylase and the reversibility of the salt effects, a new method for its purification from crude extracts was developed.