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. Author manuscript; available in PMC: 2007 Nov 1.
Published in final edited form as: Arch Biochem Biophys. 2006 Sep 25;455(1):61–67. doi: 10.1016/j.abb.2006.08.024

Table 4.

Testosterone hydroxylation by 2B4dH/H226Y and mutants at 200 μM substrate.

Turn over (nmol/min/nmol P450) Stereoselectivity Regioselectivity
P450 16α-OH 16β-OH 2α-OH 16α-OH:16β-OH 16-OH:2-OH
2B4dH/H226Y 0.43 0.06 0.17 7.2 2.9
V292A 0.26 ND 0.13 ND 2.0
F296A 0.44 ND 0.34 ND 1.3
T302A 0.01 0.03 ND 0.3 ND
I363Aa 3.7 1.4 0.51 2.7 10
V367A 0.17 0.31 0.07 0.6 6.9
V367L 0.07 ND 0.09 ND 0.80
V477A ND ND ND ND ND
V477F 0.08 0.01 0.46 8.0 0.19
a

I363A also catalyzes P450 testosterone 15α-hydroxylation (12 nmol/min/nmol P450), whereas P450 2B4dH/H226Y showed non-determinable (ND) testosterone 15α-hydroxylase activity.

Results are the mean of at least three determinations. The standard error of mean (SEM) was approximately ± 25% of the mean values. SEM was not indicated in the Table to enhance the clarity.