TABLE 2

Enzymatic activities for reported test substrates by recombinant 6×His-tagged AKR and CBR wild-type and variant allele enzymes

Values correspond to mean ± S.D. obtained from three experiments performed with three independent enzyme preparations (n = 9) for each isoform. Reported activities for the wild-type enzymes are also given for comparison purposes.

EnzymeVariantSubstrateActivityReported Activities
nmol/min · mg protein
AKR1B1dl-Glyceraldehyde354 ± 48441 ± 14 (O'Connor et al., 1999)
I15F287 ± 36
H42L347 ± 42
L73V342 ± 25
K90E336 ± 51
G204S327 ± 45
T288I313 ± 45
AKR1B10(S)-1-indanol980 ± 801000 (Martin et al., 2006)
P87S870 ± 90
M286T820 ± 90
D313N900 ± 50
AKR1C11-Acenaphthenol2050 ± 2002100 (Burczynski et al., 1998); 1800 (Byrns et al., 2008)
R170H1891 ± 164
Q172L1870 ± 149
AKR1C21-Acenaphthenol2980 ± 1512500 (Burczynski et al., 1998); 2230 ± 80 (Takahashi et al., 2008); 2400 (Byrns et al., 2008)
F46Y2075 ± 170*
AKR1C3R66Q1-Acenaphthenol3370 ± 1602800 (Burczynski et al.,1998)
H5Q3380 ± 53
R66Q3078 ± 276
A106T2060 ± 81*
R170C2298 ± 115*
P180S2410 ± 165*
AKR1C41-Acenaphthenol1660 ± 1901951 ± 49 (O'Connor et al., 1999)
G135E1484 ± 181
S145C1820 ± 121
L311V958 ± 132*
AKR7A29,10-Phenanthrenequinone2553 ± 2293100 ± 107 (O'Connor et al., 1999)
V135M2385 ± 295
A142T1660 ± 130*
Q157H2425 ± 237
E180K2303 ± 247
G198S2483 ± 271
S255N2450 ± 230
CBR4Menadionekcat/Km = 0.34 ± 0.07 min−1 · μM−1kcat/Km = 0.35 min−1 · μM−1 (Endo et al., 2008)
L70Mkcat/Km = 0.32 ± 0.07 min−1 · μM−1

  • ↵* Variants significantly different from their respective wild-type enzymes (P < 0.05).