Recent Data on the Active Centre of Amylolytic Enzymes

Abstract

Abstract The amount and configuration of products formed from starch are determined by the size, the structure and the functional groups of the active centre of amylolytic enzymes. In a previous publication we had determined the role of histidil and tyrosil side chains in the case of amylolytic enzymes. In this paper we have studied the role of tryptophyl‐, amino‐ and carboxyl groups. For this purpose the above groups have been modified by specific chemical reactions and the effect of modification on substrate binding and product formation has been determined for each enzyme. Subsite maps of the individual enzymes were prepared on the basis of the probability of bond scission of 14 C‐labelled maltodextrines. The effect of the modification of above functional groups on changes in the subsite maps has been determined. On the basis of the above, the individual functional groups could be located within the active centre. With knowledge and appropriate modification of the site of given functional groups the product spectrum of the individual α‐amylases could be changed. By this method, starch decomposition can be performed as required by practical demands.