FIG. 7.
Hemadsorption activity of HN interface mutants and wild-type HN after a shift from 4°C to 37°C. Erythrocytes were adsorbed for 30 min in the cold to monolayers expressing either wild-type (wt) HN or F220N, F220Y, S222K, L224Q, or L224S HN. Plates were either washed immediately with cold phosphate-buffered saline with calcium and magnesium or shifted to 37°C for either 10, 20, or 30 min before washing. Hemadsorption (HAd) activity was quantitated spectrophotometrically as described previously. Each point indicates the percentage of hemadsorption remaining from the control plates, which were not shifted to the higher temperature, and represents an average of two determinations.