TABLE 2.

Characterization of wild-type and R292K mutant neuraminidases

Enzyme	Substratea		Ki (nM)b
	Km (μM)	Relative Vmax	GS 4071	Zanamivir	4-Amino-Neu5Ac2en
Wild type	84	17	0.13 (3.25 × 10−6)	0.33 (8.25 × 10−6)	100 (2.50 × 10−3)
Mutant	337	1	3,600 (2.00 × 10−2)	8.0 (4.44 × 10−5)	3,000 (1.67 × 10−2)

^aK_m and relative V_max values were determined by using MUNANA as substrate and are average values from at least three separate experiments using different virus preparations. 

^bK_i values were determined as described in reference 23 and are average values from two independent experiments. Numbers shown in parentheses indicate the K_i/K_m ratio as an indicator of relative inhibitory efficiency.