Effect of sialidase on blood group specificity of hog submaxillary glycoproteins.

Hogs can be divided into three phenotypes A, H and In, depending on the ability of extracts of their submaxillary glands to inhibit the agglutination of human A cells with human anti-A, and human O cells with eel-anti-H serum. Evidence is here provided that the inactive glycoprotein, In, represents H active glycoprotein containing additional N-glycolyl neuraminic acid, which stereospecifically masks the H determinant, alpha (1 --> 2)-L-fucosyl residue.