. Author manuscript; available in PMC: 2009 Nov 10.

Published in final edited form as: Biochemistry. 2009 Jun 30;48(25):5963–5971. doi: 10.1021/bi900140c

Table 4.

Calculated activation barriers and rate constants for the hydrolysis for the dGTP analogues in the gas phase.

X	pK_a	^Δ E^≠_calc,gas	k	log(k)
O	8.9	23.6	1862.1	3.27
CHF	9.0	30.5	2.45	0.39
CHCl	9.5	30.0	1.66	0.22
CHBr	9.9	34.9	0.04	−1.45
CH₂	10.5	32.0	0.56	−0.24
CF₂	7.8	25.5	263.0	2.42
CFCl	8.4	27.1	64.6	1.81
CCl₂	8.9	33.9	0.09	−1.03
CBr₂	9.3	33.7	0.11	−0.94

ΔE^≠_calc,gas denotes the calculated activation barrier for each compound, and k denotes the corresponding rate constant, as obtained from transition state theory (assuming a temperature of 250°C).