Cell surface labeling of erythrocyte glycoproteins by galactose oxidase and Mn++-catalyzed coupling reaction with methionine sulfone hydrazide.

Methionine sulfone hydrazide (MSH) was coupled to 6-aldehydosugars and the reaction was found to be catalytically enhanced by Mn⁺⁺ ion under physiological condition. The reaction was applied to label surface glycoproteins of erythrocytes with ³⁵S]-MSH after treating cells with galactose oxidase. The slab gel electrophoretic pattern of surface glycoproteins in sodium dodecylsulfate-polyacrylamide can be printed on autoradiogram. At least ten glycoproteins of normal human erythrocytes were printed; five (c, d, e, g, and k) were major bands, and of these four (c, d, e, and g) corresponded to “PAS I, II′, II, and III”. Others are hitherto unrecognized. Two intense bands each corresponds to c, and g, and two new bands, d′ and e′, were printed in desialylated fetal erythrocytes; intact fetal erythrocytes did not show significant label.