title: The effects of single nucleotide polymorphisms in CYP2A13 on metabolism of 5-methoxypsoralen.
abstract: A number of studies have demonstrated that cytochrome P450 (P450) converts furanocoumarin derivatives into reactive molecules, which form covalent bonds to biomolecules. 5-Methoxypsoralen (5-MOP) is a natural furanocoumarin from apiaceous plants. In this study, we examined the effect on 5-MOP metabolism of single nucleotide polymorphisms (SNPs) in CYP2A13. We used Escherichia coli-generated recombinant enzymes of wild-type CYP2A13*1 and five variants, CYP2A13*4 (R101Q), CYP2A13*5 (F453Y), CYP2A13*6 (R494C), CYP2A13*8 (D158E), and CYP2A13*9 (V323L). In high-performance liquid chromatography analyses of 5-MOP metabolic products, CYP2A13*1 converted 5-MOP into 5-MOP dihydrodiol; K(m) and V(max) values of the reaction were 1.44 ± 0.17 μM and 4.23 ± 0.36 nmol/(min · nmol P450), respectively. The generation of a dihydrodiol from 5-MOP implies that conversion by CYP2A13 causes toxicity due to the formation of covalent bonds with DNA or proteins. Most of the CYP2A13 variants could metabolize 5-MOP; K(m) values for CYP2A13*5, *6, *8, and *9 were 1.63 ± 0.12, 1.36 ± 0.10, 0.85 ± 0.09, and 0.58 ± 0.06 μM, respectively, and V(max) values were 3.20 ± 0.13, 4.69 ± 0.13, 2.34 ± 0.07, and 1.84 ± 0.09 nmol/(min · nmol P450), respectively. However, the processing of 5-MOP by CYP2A13*4 was not detectable. Based on this data, we hypothesize that SNPs within the CYP2A13 gene affect metabolism of 5-MOP in humans.
authors.affiliation: Research Center for Environmental Genomics, Kobe University, Rokkodaicho 1-1, Nada, Kobe 657-8501, Japan.
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Goto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriuchi
authors.forename: Xuejun
authors.initials: X
authors.lastname: Fu
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Ikegawa
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Matsubara
authors.forename: Gang
authors.initials: G
authors.lastname: Chang
authors.forename: Tomohide
authors.initials: T
authors.lastname: Uno
authors.forename: Kenichi
authors.initials: K
authors.lastname: Morigaki
authors.forename: Kunio
authors.initials: K
authors.lastname: Isshiki
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Imaishi
mesh_terms: D000078223:5-Methoxypsoralen; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics* / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008730:Methoxsalen / Q000031:analogs & derivatives* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D000078223:5-Methoxypsoralen; D001189:Aryl Hydrocarbon Hydroxylases; C414206:CYP2A13 protein, human; D008730:Methoxsalen