Peroxynitrite oxidizes erythrocyte membrane band 3 protein and diminishes its anion transport capacity.
We describe an altered membrane band 3 protein-mediated anion transport in erythrocytes exposed to peroxynitrite, and relate the loss of anion transport to cell damage and to band 3 oxidative modifications. We found that peroxynitrite down-regulate anion transport in a dose dependent relation (100-300 micromoles/l). Hemoglobin oxidation was found at all peroxynitrite concentrations studied. A dose-dependent band 3 protein crosslinking and tyrosine nitration were also observed. Band 3 protein modifications were concomitant with a decrease in transport activity. ( - )-Epicatechin avoids band 3 protein nitration but barely affects its transport capacity, suggesting that both processes are unrelated. N-acetyl cysteine partially reverted the loss of band 3 transport capacity. It is concluded that peroxynitrite promotes a decrease in anion transport that is partially due to the reversible oxidation of band 3 cysteine residues. Additionally, band 3 tyrosine nitration seems not to be relevant for the loss of its anion transport capacity.
Celedón
Gloria
G
Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile.
González
Gustavo
G
Pino
José
J
Lissi
Eduardo A
EA
D000111:Acetylcysteine / Q000737:chemistry; D001457:Anion Exchange Protein 1, Erythrocyte / Q000037:antagonists & inhibitors*; D000838:Anions / Q000378:metabolism; D002392:Catechin / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D017136:Ion Transport / Q000187:drug effects; D009566:Nitrates / Q000737:chemistry; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000502:physiology*; D014443:Tyrosine / Q000737:chemistry
D001457:Anion Exchange Protein 1, Erythrocyte; D000838:Anions; D006454:Hemoglobins; D009566:Nitrates; D016877:Oxidants; D030421:Peroxynitrous Acid; D014443:Tyrosine; D002392:Catechin; D000111:Acetylcysteine