NADH:Cytochrome b(5) Reductase and Cytochrome b(5) Can Act as Sole Electron Donors to Human Cytochrome P450 1A1-Mediated Oxidation and DNA Adduct Formation by Benzo[a]pyrene

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F16%3A10328594" target="_blank" >RIV/00216208:11310/16:10328594 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.chemrestox.6b00143" target="_blank" >http://dx.doi.org/10.1021/acs.chemrestox.6b00143</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.chemrestox.6b00143" target="_blank" >10.1021/acs.chemrestox.6b00143</a>

Jazyk výsledku

angličtina

Název v původním jazyce

NADH:Cytochrome b(5) Reductase and Cytochrome b(5) Can Act as Sole Electron Donors to Human Cytochrome P450 1A1-Mediated Oxidation and DNA Adduct Formation by Benzo[a]pyrene

Popis výsledku v původním jazyce

Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b(5) reductase (CBR) in the presence of cytochrome b(5) can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the coenzymes of these reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of CBR, to mediate BaP oxidation. Two systems containing human P450 1A1 were utilized: human recombinant P450 1A1 expressed with POR, CBR, epoxide hydrolase; and cytochrome b(5) in Supersomes and human recombinant 2450 1A1 reconstituted with POR and/or with CBR and cytochrome b(5) in liposomes. BaP-9,10-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, a metabolite of unknown structure, and two BaP-DNA adducts were generated by the P450 1A1=Supersomes system, both in the presence of NADPH and in the presence of NADH. The major BaP-DNA adduct detected by P-32-postlabeling was characterized as 10-(deoxyguanosin-N-2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-BaP (assigned adduct 1), while the minor adduct is probably a guanine adduct derived from 9-hydroxy-BaP-4,5-epoxide (assigned adduct 2). BaP-3-ol as the major metabolite, BaP-9-ol, BaP-1,6-dione, BaP-3,6-dione, an unknown metabolite, and adduct 2 were observed in the system using P450 1A1 reconstituted with POR plus NADPH. When P450 1A1 was reconstituted with CBR and cytochrome b(5) plus NADH, BaP-3-ol was the predominant metabolite too, and an adduct 2 was also generated. Our results demonstrate that the NADH/cytochrome b(5)/CBR system can act as the sole electron donor both for the first and second reduction of P450 1A1 during the oxidation of BaP in vitro. They suggest that NADH-dependent CBR can replace NADPH-dependent POR in the P450 1A1-catalyzed metabolism of BaP.

Název v anglickém jazyce

NADH:Cytochrome b(5) Reductase and Cytochrome b(5) Can Act as Sole Electron Donors to Human Cytochrome P450 1A1-Mediated Oxidation and DNA Adduct Formation by Benzo[a]pyrene

Popis výsledku anglicky

Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b(5) reductase (CBR) in the presence of cytochrome b(5) can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the coenzymes of these reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of CBR, to mediate BaP oxidation. Two systems containing human P450 1A1 were utilized: human recombinant P450 1A1 expressed with POR, CBR, epoxide hydrolase; and cytochrome b(5) in Supersomes and human recombinant 2450 1A1 reconstituted with POR and/or with CBR and cytochrome b(5) in liposomes. BaP-9,10-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, a metabolite of unknown structure, and two BaP-DNA adducts were generated by the P450 1A1=Supersomes system, both in the presence of NADPH and in the presence of NADH. The major BaP-DNA adduct detected by P-32-postlabeling was characterized as 10-(deoxyguanosin-N-2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-BaP (assigned adduct 1), while the minor adduct is probably a guanine adduct derived from 9-hydroxy-BaP-4,5-epoxide (assigned adduct 2). BaP-3-ol as the major metabolite, BaP-9-ol, BaP-1,6-dione, BaP-3,6-dione, an unknown metabolite, and adduct 2 were observed in the system using P450 1A1 reconstituted with POR plus NADPH. When P450 1A1 was reconstituted with CBR and cytochrome b(5) plus NADH, BaP-3-ol was the predominant metabolite too, and an adduct 2 was also generated. Our results demonstrate that the NADH/cytochrome b(5)/CBR system can act as the sole electron donor both for the first and second reduction of P450 1A1 during the oxidation of BaP in vitro. They suggest that NADH-dependent CBR can replace NADPH-dependent POR in the P450 1A1-catalyzed metabolism of BaP.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CE - Biochemie

OECD FORD obor

—

Projekt

<a href="/cs/project/GA14-18344S" target="_blank" >GA14-18344S: Vývoj nanočástic obsahujících cytostatika a enzymy pro zlepšení chemotherapie lidských neuroblastomů a studium mechanismu jejich působení</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Chemical Research in Toxicology

ISSN

0893-228X

e-ISSN

—

Svazek periodika

29

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

1325-1334

Kód UT WoS článku

000381593500009

EID výsledku v databázi Scopus

2-s2.0-84982300259