Functional influence of human CYP2D6 allelic variations: P34S, E418K, S486T, and R296C

다국어 초록 (Multilingual Abstract)

CYP2D6 is responsible for the oxidativemetabolism of 20–25 % of clinical drugs and its geneticpolymorphisms can significantly influence the drugmetabolism. In this study, we analyzed the functionalactivities of four nonsynonymous single nucleotide polymorphismsfrom CYP2D6*52 allele, which were recentlyfound, and one found frequently in CYP2D6 alleles.
Recombinant variant enzymes of E418K, S486T, andR296C were successfully expressed in Escherichia coli andpurified. However, a CYP holoenzyme spectrum of P34Svariant was not detected in E. coli whole cell level.
Structural analysis indicated that P34S mutation seemed toperturb a highly conserved proline-rich N-terminus ofCYP2D6. Steady state kinetic analyses showed the significantreductions of enzymatic activities in E418K andR296C variants. In the case of bufuralol 1’-hydroxylation,a novel mutant, E418K, showed 32 % decrease in catalyticefficiency (kcat/Km) mainly due to the decrease of kcatvalue. R296C showed much greater reduction in the catalyticefficiency (9 % of wild-type) due to both of a decrease of kcat value and an increase of Km value. In the case ofdextromethorphan O-demethylation, E418K showed bothof a decrease of kcat value and an increase Km value toresult in *43 % reduction of catalytic efficiency. A highlydecreased catalytic efficiency (*6 % of wild-type) in themutant of R296C also was observed mainly due to thedramatic change of kcat value of dextromethorphanO-demethylation. These results suggested that individualscarrying these allelic variants are likely to have the alteredmetabolic abilities of many clinical drugs therefore, thesepolymorphisms of CYP2D6 should be much concerned forreliable drug treatment.

참고문헌 (Reference)

1 Matsunaga, M., "Two novel CYP2D6*10 haplotypes as possible causes of a poor metabolic phenotype in Japanese" 37 : 699-701, 2009

2 Songhee HAN, "Self-Sufficient Catalytic System of Human Cytochrome P450 4A11 and NADPH-P450 Reductase" 한국응용약물학회 17 (17): 156-161, 2009

3 Guengerich, F. P, "Role of cytochrome P450 enzymes in drug– drug interactions" 43 : 7-35, 1997

4 Im-Soon Lee, "Polymorphic Metabolism by Functional Alterations of Human Cytochrome P450 Enzymes" 대한약학회 34 (34): 1799-1816, 2011

5 Hanna, I. H., "Heterologous expression of cytochrome P450 2D6 mutants, electron transfer, and catalysis of bufuralol hydroxylation : the role of aspartate 301 in structural integrity" 393 : 255-261, 2001

6 Johansson, I., "Genetic analysis of the Chinese cytochrome P4502D locus : characterization of variant CYP2D6 genes present in subjects with diminished capacity for debrisoquine hydroxylation" 46 : 452-459, 1994

7 Zhou, H., "Functional characterization of four allelic variants of human cytochrome P450 1A2" 422 : 23-30, 2004

8 Han, S., "Functional characterization of allelic variants of polymorphic human cytochrome P450 2A6(CYP2A6*5, *7, *8, *18, *19, and *35)" 35 : 394-399, 2012

9 Sakuyama, K., "Functional characterization of 17 CYP2D6 allelic variants(CYP2D6. 2, 10, 14A-B, 18, 27, 36, 39, 47-51, 53-55, and 57)" 36 : 2460-2467, 2008

10 이혜자, "Expression of CYP2A6, CYP2D6 and CYP4A11 Polymorphisms in COS7 Mammalian Cell Line" 한국독성학회 27 (27): 25-29, 2011

11 Wu, Z. L., "Enhanced bacterial expression of several mammalian cytochrome P450 s by codon optimization and chaperone coexpression" 31 : 1589-1593, 2009

12 Lee, S. J., "Discovery of novel functional variants and extensive evaluation of CYP2D6 genetic polymorphisms in Koreans" 37 : 1464-1470, 2009

13 Rowland, P., "Crystal structure of human cytochrome P450 2D6" 281 : 7614-7622, 2006

14 Yu, A., "Comparative contribution to dextromethorphan metabolism by cytochrome P450 isoforms in vitro: can dextromethorphan be used as a dual probe for both CTP2D6 and CYP3A activities?" 29 : 1514-1520, 2001

15 Stark, K., "Characterization of orphan human cytochromes P450" 39 : 627-637, 2007

16 Gaedigk, A., "CYP2D6*36 gene arrangements within the cyp2d6 locus : association of CYP2D6*36 with poor metabolizer status" 34 : 563-569, 2006