Binding of influenza virus to a reconstituted receptor complex containing glycophorin

Membrane particles possessing receptor activity for influenza virions have been reconstituted following solubilization of human erythrocyte membranes with octylglucoside (OG) and fractionation on a DEAE-cellulose column. Fractions that eluted with 1.5 M NaCl yielded, after removal of OG, reconstituted membrane particles (RMP) which could bind virus and inhibit hemagglutination. RMP contained essentially two membrane proteins (glycophorin and a nonglycosylated protein of molecular weight 29,000), two phospholipids (sphingomyelin and phosphatidylcholine), cholesterol, and gangliosides. Incubation of influenza virus with RMP at 4 degrees resulted in the formation of a virus-RMP complex (liposomes). The specificity of the receptor was demonstrated by inhibition of viral attachment when RMP were treated with neuraminidase or preincubated with rabbit anti-M or anti-N antiserum, suggesting that both the carbohydrates and peptide moiety may play a role in attachment. Calculations suggest that there are 6 X 10(3) N-acetyl neuraminic acid residues per attached virion. This system provides a simple and gentle means of reconstituting membrane components to study receptor activity.