Enzymatic removal of oxidized protein aggregates from erythrocyte membranes

Citation
T. Fujino et al., Enzymatic removal of oxidized protein aggregates from erythrocyte membranes, J BIOCHEM, 127(6), 2000, pp. 1081-1086
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOCHEMISTRY
ISSN journal
0021-924X → ACNP
Volume
127
Issue
6
Year of publication
2000
Pages
1081 - 1086
Database
ISI
SICI code
0021-924X(200006)127:6<1081:EROOPA>2.0.ZU;2-E
Abstract
Erythrocytes oxidized or aged in the circulation undergo membrane protein a ggregation and anti-band 3 autoantibody binding to the cell surface. When h uman erythrocytes were mildly oxidized in vitro with 0.1 mM Fe(III) at 37 d egrees C for 3 h, the aggregation of nonionic detergent C12E8-insoluble mem brane protein and the binding of anti-band 3 IgG to the cell surface were i ncreased. Incubation of membranes isolated from the oxidized cells increase d the amount of protein aggregates by 5-fold after 6 h, while incubation fo r a further 12 h sharply decreased the amount of aggregates. In the presenc e of diisopropyl fluorophosphate (DFP), however, the increased amount of ag gregates was maintained in the subsequent incubation, Western blot analysis of the aggregates using rabbit anti-band 3 showed that band 3 protein aggr egates increased in the initial stage of incubation and decreased upon subs equent incubation, whereas the increased band 3 protein aggregates did not subsequently decrease when membranes were incubated in the presence of DFP. Incubation of the oxidized cells at 37 degrees C for 18 h caused reduction of the membrane protein aggregates and the I-125-anti-band 3 IgG binding t o the cell surface, while incubation in the presence of DFP did not cause t hese reductions. The results suggest that the oxidation-induced cell membra ne protein aggregates were probably removed by 80-kDa serine protease, name ly, oxidized protein hydrolase (OPH), in the oxidized cell membranes [Fujin o et al. (1998) Biochim. Biophys. Acta 1374, 47-54; (1998) J. Biochem. 124, 1077-1085; (2000) Biochim, Biophys. Acta 1478, 102-112], and as a result t he increased anti-band 3 binding to the cell surface was reduced.