The role of protein carboxyl groups in carbohydrate-concanavalin a interaction

Abstract

1. 1. The role of carboxyl groups in the binding of specific carbohydrates to concanavalin A, the phytohemagglutinin of the jack bean, has been studied using two techniques: (1) H+ titration in the presence and absence of methyl [alpha]--mannopyranoside, a specifically bound carbohydrate ligand and (2) chemical modification of the protein carboxyl groups employing glycine methyl ester and a water-soluble carbodiimide, in the presence and absence of the mannoside.2. 2. It is shown that protein carboxyl groups are masked when concanavalin A is titrated in the presence of the sugar hapten and that this sugar glycoside also protects protein carboxyl groups from modification with glycine methyl ester.