Enhanced reaction with Vicia graminea lectin and exposed terminal N− acetyl-D-glucosaminyl residues on a sample of human red cells with Hb M− Hyde Park

A sample of polyagglutinable red cells was obtained from a healthy individual (group O, N) possessing a hemoglobin (Hb) variant called Hb M-Hyde Park. The sialic acid content of the individual's red cells is 90 percent of normal, and his cells are agglutinated by monoclonal but not lectin anti-Tn, a panel of lectins specific for N-acetylgalactosamine (or galactose), and N-acetylglucosamine. Enhanced agglutination reactions were obtained with Vicia graminea, Ulex europaeus, and human anti-I and -i. Using various enzyme treatments and different methods of labeling cell surface components, two defective cell membrane sites have been identified: one associated with the O-linked oligosaccharides on sialoglycoproteins and the other associated with exposed N-acetylglucosaminyl residues located on membrane components of apparent molecular weights 88,000 to 130,000 and 46,000 to 73,000 (probably the Band 3 and Band 4.5 regions, respectively).