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ABH antigens as recognition sites for the activation of red blood cell anion exchange by the lectin Ulex europaeus agglutinin I
Author(s) -
Engelmann Bernd
Publication year - 1993
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041570224
Subject(s) - dids , agglutinin , lectin , chemistry , ulex europaeus , fucose , bicarbonate , biochemistry , extracellular , antigen , red blood cell , biology , glycoprotein , immunology , organic chemistry , membrane
The blood group antigen H (blood group O) and fucose‐specific lectin Ulex europaeus agglutinin I (UEA 1 ) (10 μg/ml) was found to increase the rate constant of CL − efflux into 100mM Na + oxalate media by about 40% in erythrocytes taken from antigen H donors. In 100 mMK + oxalate, 150 mM Na + pyruvate and in 150 mM Na + acetate media the lectin elevated the rate constant of CL − efflux by 20–50%. The acceleration of Cl − efflux by UEA 1 was completely blocked by 10 μM 4,4′‐dllsothiocyanato‐stilbene‐2,2′‐disulfonic acid (DIDS) indicating that the effect of the lectin is mediated by the anion exchanger of human erythrocytes (band 3 protein). In antigen A 1 erythrocytes no significant stimulation of anion exchange by UEA 1 was seen. The activation of Cl − efflux was completely prevented by addition of 1 mM fucose to the medium. These results suggest that the effect of UEA 1 is mediated through interaction with the fucose residues of H antigens. Increasing extracellular Ca ++ from 0.5 to 5 mM in Na + pyruvate or Na + acetate media slightly reduced the acceleration of anion exchange by the lectin. On the other hand, replacing part of extracellular chloride by bicarbonate did not considerably alter the (previously reported) stimulatory effect of UEA 1 on red blood cell Ca ++ uptake. This suggests that the acceleration of anion exchange and of Ca ++ uptake by UEA 1 , respectively, are mediated by different mechanisms. It is concluded that UEA 1 activates anion exchange of human erythrocytes most probably by a direct interaction with H antigens present on extracellular domains of the band 3 protein. © 1993 Wiley‐Liss, Inc.