TY - JOUR
T1 - Role of the conserved threonine 309 in mechanism of oxidation by cytochrome P450 2D6
AU - Keizers, P.H.J.
AU - Schraven, L.H.
AU - de Graaf, C.
AU - Hidestrand, M.
AU - Ingelman-Sundberg, M.
AU - van Dijk, B.M.
AU - Vermeulen, N.P.E.
AU - Commandeur, J.N.M.
PY - 2005
Y1 - 2005
N2 - Based on sequence alignments and homology modeling, threonine 309 in cytochrome P450 2D6 (CYP2D6) is proposed to be the conserved I-helix threonine, which is supposed to be involved in dioxygen activation by CYPs. The T309V mutant of CYP2D6 displayed a strong shift from O-dealkylation to N-dealkylation reactions in oxidation of dextromethorphan and 3,4- methylenedioxymethylamphetamine. This may be explained by an elevated ratio of hydroperoxo-iron to oxenoid-iron of the oxygenating species. In consistence, using cumene hydroperoxide, which directly forms the oxenoid-iron, the T309V mutant again selectively catalyzed the O-dealkylation reactions. The changed ratio of oxygenating species can also explain the decreased activity and changed regioselectivity that were observed in 7-methoxy-4-(aminomethyl)-coumarin and bufuralol oxidation, respectively, by the T309V mutant. Interestingly, the T309V mutant always showed a significantly increased, up to 75-fold, higher activity compared to that of the wild-type when using cumene hydroperoxide. These results indicate that T309 in CYP2D6 is involved in maintaining the balance of multiple oxygenating species and thus influences substrate and regioselectivity. © 2005 Elsevier Inc. All rights reserved.
AB - Based on sequence alignments and homology modeling, threonine 309 in cytochrome P450 2D6 (CYP2D6) is proposed to be the conserved I-helix threonine, which is supposed to be involved in dioxygen activation by CYPs. The T309V mutant of CYP2D6 displayed a strong shift from O-dealkylation to N-dealkylation reactions in oxidation of dextromethorphan and 3,4- methylenedioxymethylamphetamine. This may be explained by an elevated ratio of hydroperoxo-iron to oxenoid-iron of the oxygenating species. In consistence, using cumene hydroperoxide, which directly forms the oxenoid-iron, the T309V mutant again selectively catalyzed the O-dealkylation reactions. The changed ratio of oxygenating species can also explain the decreased activity and changed regioselectivity that were observed in 7-methoxy-4-(aminomethyl)-coumarin and bufuralol oxidation, respectively, by the T309V mutant. Interestingly, the T309V mutant always showed a significantly increased, up to 75-fold, higher activity compared to that of the wild-type when using cumene hydroperoxide. These results indicate that T309 in CYP2D6 is involved in maintaining the balance of multiple oxygenating species and thus influences substrate and regioselectivity. © 2005 Elsevier Inc. All rights reserved.
U2 - 10.1016/j.bbrc.2005.10.066
DO - 10.1016/j.bbrc.2005.10.066
M3 - Article
SN - 0006-291X
VL - 338
SP - 1065
EP - 1074
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -