TABLE 1.

Properties of NDV-B1 HN interface mutants^a

HN function	% of control
	F220A	S222K
Fusion	9.6 ± 5.6	9.1 ± 2.7
Cell surface expression	71.4 ± 4.0	64.3 ± 3.6
Hemadsorption
4°C	64.6 ± 16.3	47.0 ± 11.7
37°C	29.6 ± 6.4	29.9 ± 11.0
NAb	58.5 ± 4.8	61.7 ± 6.2

^aAll values are expressed as the percentage of wild-type NDV-B1 HN activity.

^bCorrected for differences in cell surface expression.