Abstract
Snail agglutinin (anti-A(EC), anti-A, of cold agglutinin type) from the albumin gland of Euhadra callizona amaliae was purified by affinity chromatography (meconium-A aminoethyl cellulose). Its physicochemical properties are as follows: S(20,w): 5.3S. Iso-electric point: pH 3.6. Molecular weight: 8.9x10^4. Hexose content: 5.1%. The amino acid composition is that of an acidic protein. The agglutination is inhibited by Ga1NAc, GNAc, raffinose, and melibiose at low concentration. It does not agglutinate B- and O-RDE-treated human red cells. Some blood group A-active substances (secretor A saliva and hog gastric mucin A + H) have low potency to inhibit the agglutination. Anti-A(EC) has no ability to release the cellfixed anti-Forssman haemolysin and the cell-fixed blood group A-decomposing enzyme. The significance of the antigen distribution on the limited area of the erythrocyte and protein surface is also discussed. Precipitin reaction of this agglutinin with various blood group-active substances has shown that anti-A(EC) is directed to a narrow-range spectrum of determining antigenicity