Glycosylation site of band 3, the human erythrocyte anion-exchange protein.
The band 3 protein has a single glycosylation site on the carboxy-terminal 55 000-dalton tryptic fragment that defines a sequence of the polypeptide on the extracytoplasmic surface of the cell. To locate this site, a novel procedure involving end labeling of the 55 000-dalton tryptic fragment was used. Peptides resulting from partial proteolysis of the end radiolabeled glycoprotein were separated by lectin-Sepharose chromatography and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The smallest fragment observed defined the distance between the glycosylation site and the amino terminus. The procedure was first tested on a protein for which the location of the glycosylation site is known, HLA-B7 antigen. It was then used to show that the glycosylation site of human band 3 is 28 000 +/- 3000 daltons from the carboxy terminus of the protein.
D001457:Anion Exchange Protein 1, Erythrocyte / Q000302:isolation & purification*; D002241:Carbohydrates / Q000032:analysis; D002918:Chymotrypsin; D006023:Glycoproteins / Q000097:blood; D006027:Glycosides; D006680:HLA Antigens; D015793:HLA-B7 Antigen; D006801:Humans; D037102:Lectins; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D014357:Trypsin; D014909:Wheat Germ Agglutinins
D001457:Anion Exchange Protein 1, Erythrocyte; D002241:Carbohydrates; D006023:Glycoproteins; D006027:Glycosides; D006680:HLA Antigens; D015793:HLA-B7 Antigen; D037102:Lectins; D010446:Peptide Fragments; D014909:Wheat Germ Agglutinins; D002918:Chymotrypsin; D014357:Trypsin