Skip to main content
. 2009 Jul 21;284(39):26439–26446. doi: 10.1074/jbc.M109.012500

TABLE 3.

Kinetic constants for inhibition of nucleotide incorporation by PFA

Enzyme IC50a Foldb change Kic Fold change
μm μm
UL54d 0.87e Referencef 0.076 Reference
RT 0.60 1.4Sg 1.1 14
gp43 333 380R NAh NA
gp43 333 Reference NA NA
A 7.5 44S NA NA
ABC 3.3 100S NA NA
A 7.5 Reference 0.99 Reference
A/V781I 19.7 2.6R 1.8 1.8R
ABC 3.3 Reference 0.55 Reference
ABC/R784A 37 11R 5.9 11R
ABC/Q807A 27 8.2R 6.1 11R

a IC50 is the inhibitory concentration of PFA that reduced the nucleotide incorporation activity of enzyme by 50%. Values were calculated by fitting at least 10 data points to a sigmoidal dose-response (variable slope) equation using GraphPad Prism (version 5.0).

b Fold change is calculated as the ratio of the IC50 or Ki values of the reference and the query enzyme in the subgroup such that the ratio is more than 1.

c Ki is the inhibitor dissociation constant. Values were calculated by globally fitting the 42-data point Ki experiment to the general mixed model of inhibition using GraphPad Prism (version 5.0).

d The HCMV polymerase UL54 was expressed in the in vitro transcription/translation system.

e Standard deviations were determined on the basis of at least three independent experiments and represent a maximum of 25% of the reported value.

f Reference defines the enzyme whose inhibitory constants were used as a reference value in the subgroup. Subgroups of enzymes are separated by an extra row.

g Superscript R and S indicate resistance and sensitivity, respectively, and illustrate fold changes in resistance or sensitivity to PFA with respect to the reference enzyme in the subgroup.

h NA means not available.