Naturally occurring anti-band 3 antibodies bind to protein rather than to carbohydrate on band 3.
Naturally occurring anti-band 3 antibodies were affinity purified from pooled human IgG (Sandoglobulin) (Lutz, H. U., Flepp, R., and Stringaro-Wipf, G. (1984) J. Immunol. 133, 2610-2618). They bound to the major integral membrane protein of human red blood cells and its 55-kDa NH2-terminal chymotryptic fragment but not to the carbohydrate-rich 38-kDa fragment on blots. Likewise, neither an endo-beta-galactosidase nor a neuraminidase treatment of band 3 on intact red cells reduced their binding to the blotted antigen. Lactoferrin (10 micrograms/ml) had no significant effect on their binding to band 3 and to its 55-kDa chymotryptic fragment. Even in the presence of 20 micrograms/ml lactoferrin anti-band 3 antibodies bound specifically to chymotrypsin-pretreated and oxidatively stressed red cells. Thus, naturally occurring anti-band 3 antibodies bind to protein rather than carbohydrate within band 3 protein, irrespectively of whether the antibodies were depleted of anti-idiotypic and other IgG-reactive antibodies or not.
Lutz
H U
HU
Laboratory for Biochemistry, Swiss Federal Institute of Technology, ETH-Zentrum, Zurich.
Gianora
O
O
Nater
M
M
Schweizer
E
E
Stammler
P
P
D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000276:immunology*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D015153:Blotting, Western; D002241:Carbohydrates / Q000276:immunology; D000939:Epitopes / Q000737:chemistry; D004910:Erythrocyte Membrane / Q000276:immunology; D006023:Glycoproteins / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D010446:Peptide Fragments / Q000276:immunology
D001457:Anion Exchange Protein 1, Erythrocyte; D001323:Autoantibodies; D002241:Carbohydrates; D000939:Epitopes; D006023:Glycoproteins; D010446:Peptide Fragments