Five structurally related proteins from affinity-purified Maclura pomifera lectin

Abstract
Affinity-purified M. pomifera lectin (MPL) elutes from a gel filtration column as a single symmetrical peak with characteristics expected for a single protein of .apprx. 40,000 daltons. This material can be dissociated into 2 dissimilar polypeptide chains of .apprx. 10,000 daltons. Ion-exchange chromatography on DEAE-cellulose resolves affinity-purified MPL into 5 components. These proteins are structurally related and contain varying proportions of the 2 polypeptide chains. Two of these tetrameric lectins, each composed solely of 1 of these chains, display differences in mobility during discontinuous polyacrylamide gel electrophoresis and ion-exchange chromatography but display no detectable differences in hemagglutination of human erythrocytes and interactions with carbohydrates.