GLYCOPHORIN AS A RECEPTOR FOR SENDAI VIRUS

Glycophorin A was reconstituted into large unilamellar vesicles of egg phosphatidylcholine by detergent dialysis, The observed overall rate of Sendai virus fusion increased approximately 4-fold between 0 and 0. 006 mol % glycophorin, roughly proportional to the glycophorin content . However, no further increase in rate was observed at 0.02 mol % glyc ophorin. Treatment of reassembled glycophorin-liposomes with neuramini dase resulted in a significant decrease in the percent of viral fusion , confirming that the presence of sialic acid residues on glycophorin is essential for its role as a receptor. The sialic acid-containing gl ycolipid, the ganglioside GD(1a), was also incorporated into phosphati dylcholine liposomes, either in addition to or in place of glycophorin A. Comparing, on the basis of sialic acid content, liposomes containi ng either glycophorin or GD(1a), comparable rates and extents of fusio n were found. However, on a molar basis glycophorin is much more effec tive. It was found that the addition of GD(1a) to glycophorin-containi ng liposomes only slightly increased the rate of fusion. This was larg ely due to an increase in the percent of virions capable of fusing.