TABLE 2.

Kinetic parameters for nucleoside 5′-triphosphate incorporation by HCV NS5B polymerase

NTP substrate	Kd,appa (μM)	kpola (s−1)	Incorporation efficiencyb	Selectivityc
ATP	1.4 ± 0.9	1.3 ± 0.6	0.9
2′-C-Methyl-DAPN-TP	37 ± 1.0	0.05 ± 0.02	0.001	900
GTP	4.1 ± 1.6	4.1 ± 0.9	1.0
2′-C-Methyl-GTP	9.6 ± 1.9	0.7 ± 0.3	0.07	13.3

^aKinetic parameters were calculated based on at least two separate replicates ± standard deviations (see Fig. 3 for additional information).

^bIncorporation efficiency was determined as k_pol/K_d,app for each NTP.

^cSelectivity was determined as (k_pol/K_d,app)_NTP/(k_pol/K_d,app)_rNAI-TP.