The mechanism of carbohydrate action. Part II. α-Amylolysis of linear substrates

The end-products of the action of purified salivary α-amylase on amylose and the maltodextrins derived from it have been examined. Only two end-products are found, namely, maltose and maltotriose. This examination supports the theory of α-amylase action first advanced by Meyer and Bernfeld, which states that in an amylose-type chain, α-amylase can hydrolyse any except the two terminal α-1:4-linkages. The ratios of maltose to maltotriose which are produced by α-amylolysis of these substrates are found to be in exact agreement with values obtained by calculation on the basis of Meyer's theory. It is also demonstrated that the susceptible linkages in a given substrate molecule are all hydrolysed by α-amylase at the same rate.