JBC, Vol. 253, Issue 13, 4777-4782, Jul, 1978
Reconstitution of the erythrocyte anion channel
A. H. Ross and H. M. McConnell
Band 3, the membrane protein which mediates erythrocyte anion exchange, was
purified on a concanavalin A column. Triglycerides, diglycerides,
cholesteryl esters, cholesterol, and phosphatidylcholine were found to
copurify. The column product gave at least two and probably three bands by
isoelectric focusing. Antibodies prepared against the purified Band 3
appeared to react only with the cytoplasmic face of Band 3. Vesicles
prepared with Band 3 had an accelerated uptake of SO4(2-) which could be
inhibited by 2-(j'-aminophenyl)-6-methyl benzene thiazo-3', 7-disulfonic
acid, a potent inhibitor of anion transport in the intact system. The
possible source of this difference is discussed. Band 3 was spin labeled,
probably at one specific site. The spectra showed that the spin label was
highly immobilized, but no dipole-dipole interactions between spin labels
on adjacent Band 3 subunits were apparent.