PMID- 15498516
OWN - NLM
STAT- MEDLINE
DCOM- 20050228
LR  - 20131121
IS  - 0006-2952 (Print)
IS  - 0006-2952 (Linking)
VI  - 68
IP  - 11
DP  - 2004 Dec 1
TI  - Influence of phenylalanine 120 on cytochrome P450 2D6 catalytic selectivity and 
      regiospecificity: crucial role in 7-methoxy-4-(aminomethyl)-coumarin metabolism.
PG  - 2263-71
AB  - The polymorphic human debrisoquine hydroxylase, cytochrome P450 2D6 (CYP2D6), is 
      one of the most important phase I drug metabolising enzymes. It is responsible 
      for metabolising a large number of compounds that mostly share similarity in 
      having a basic N-atom and an aromatic moiety. In homology modelling studies, it 
      has been suggested that in fixation of this aromatic moiety, there may be an 
      important role for phenylalanine 120 (Phe(120)). In this study, the role of 
      Phe(120) in ligand binding and catalysis was experimentally examined by mutating 
      it into an alanine. Strikingly, this substitution led to a completely abolished 
      7-methoxy-4-(aminomethyl)-coumarin (MAMC) O-demethylating activity of CYP2D6. On 
      the other hand, bufuralol metabolism was hardly affected (K(m) of 1-hydroxylation 
      mutant: 1.2 microM, wild-type: 2.9 microM, 4-hydroxylation mutant: 1.5 microM, 
      and wild-type: 3.2 microM) and neither was affected dextromethorphan 
      O-demethylation (K(m) mutant: 1.2 microM, wild-type: 2 microM, k(cat) mutant: 4.5 
      min(-1), and wild-type: 3.3 min(-1)). However, the Phe(120)Ala mutant also formed 
      3-hydroxymorphinan, the double demethylated form of dextromethorphan, which was 
      not detected using wild-type CYP2D6. 3,4-Methylenedioxymethamphetamine (MDMA) was 
      demethylenated by both mutant and wild-type CYP2D6 to 
      3,4-dihydroxymethamphetamine (3,4-OH-MA K(m) of mutant: 55 microM and wild-type: 
      2 microM). In addition, the mutant formed two additional metabolites; 
      3,4-methylenedioxyamphetamine (MDA) and 
      N-hydroxy-3,4-methylenedioxymethamphetamine (N-OH-MDMA). Inhibition experiments 
      of dextromethorphan O-demethylation showed a decreased affinity of the 
      Phe(120)Ala mutant for quinidine (IC(50) mutant: 240 nM and wild-type, 40 nM), 
      while IC(50)s for quinine were equal (1 microM). These data indicate the 
      importance of Phe(120) in the selectivity and regiospecificity in substrate 
      binding and catalysis by CYP2D6.
FAU - Keizers, Peter H J
AU  - Keizers PH
AD  - LACDR/Division of Molecular Toxicology, Department of Pharmacochemistry, Vrije 
      Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
FAU - Lussenburg, Barbara M A
AU  - Lussenburg BM
FAU - de Graaf, Chris
AU  - de Graaf C
FAU - Mentink, Letty M
AU  - Mentink LM
FAU - Vermeulen, Nico P E
AU  - Vermeulen NP
FAU - Commandeur, Jan N M
AU  - Commandeur JN
LA  - eng
PT  - Journal Article
PL  - England
TA  - Biochem Pharmacol
JT  - Biochemical pharmacology
JID - 0101032
RN  - 0 (7-methoxy-4-(aminomethyl)coumarin)
RN  - 0 (Coumarins)
RN  - 47E5O17Y3R (Phenylalanine)
RN  - 7355X3ROTS (Dextromethorphan)
RN  - EC 1.14.14.1 (Cytochrome P-450 CYP2D6)
RN  - KE1SEN21RM (N-Methyl-3,4-methylenedioxyamphetamine)
RN  - OF5P57N2ZX (Alanine)
SB  - IM
MH  - Alanine/genetics
MH  - Coumarins/*metabolism
MH  - Cytochrome P-450 CYP2D6/genetics/*metabolism
MH  - Dextromethorphan/metabolism
MH  - Humans
MH  - Models, Biological
MH  - Models, Molecular
MH  - Mutagenesis
MH  - N-Methyl-3,4-methylenedioxyamphetamine/metabolism
MH  - Phenylalanine/genetics/*metabolism
EDAT- 2004/10/23 09:00
MHDA- 2005/03/01 09:00
CRDT- 2004/10/23 09:00
PHST- 2004/05/17 00:00 [received]
PHST- 2004/08/02 00:00 [accepted]
PHST- 2004/10/23 09:00 [pubmed]
PHST- 2005/03/01 09:00 [medline]
PHST- 2004/10/23 09:00 [entrez]
AID - S0006-2952(04)00593-3 [pii]
AID - 10.1016/j.bcp.2004.08.013 [doi]
PST - ppublish
SO  - Biochem Pharmacol. 2004 Dec 1;68(11):2263-71. doi: 10.1016/j.bcp.2004.08.013.