Fig 5.

The switched HA binding preference of the Y161A virus. The biotinylated oligosaccharides indicated were used to measure saccharide binding of parental CO-HA and mutant Y161A pseudotyped viruses. The binding of graded amounts of virus (from 16 HA units to 256 HA units) to immobilized oligosaccharides was determined by measuring the binding of an anti-HA antibody as described in Materials and Methods. Wells with Y161A or CO-HA viruses alone without added oligosaccharides served as negative controls. HIV-NA pseudotyped virus binding to different saccharides was used as another negative control. All other controls, including oligosaccharides alone and the secondary antibody alone, were performed and displayed levels similar to that for the negative controls (data not shown).