Publications

• Mouse Cyp4a isoforms: enzymatic properties, gender- and strain-specific expression, and role in renal 20-hydroxyeicosatetraenoic acid formation.

  Muller D.N., Schmidt C., Barbosa-Sicard E., Wellner M., Gross V., Hercule H., Markovic M., Honeck H., Luft F.C., Schunck W.H.

  AA (arachidonic acid) hydroxylation to 20-HETE (20-hydroxyeicosatetraenoic acid) influences renal vascular and tubular function. To identify the CYP (cytochrome P450) isoforms catalysing this reaction in the mouse kidney, we analysed the substrate specificity of Cyp4a10, 4a12a, 4a12b and 4a14 and ... >> More

  AA (arachidonic acid) hydroxylation to 20-HETE (20-hydroxyeicosatetraenoic acid) influences renal vascular and tubular function. To identify the CYP (cytochrome P450) isoforms catalysing this reaction in the mouse kidney, we analysed the substrate specificity of Cyp4a10, 4a12a, 4a12b and 4a14 and determined sex- and strain-specific expressions. All recombinant enzymes showed high lauric acid hydroxylase activities. Cyp4a12a and Cyp4a12b efficiently hydroxylated AA to 20-HETE with V(max) values of approx. 10 nmol x nmol(-1) x min(-1) and K(m) values of 20-40 microM. 20-Carboxyeicosatetraenoic acid occurred as a secondary metabolite. AA hydroxylase activities were approx. 25-75-fold lower with Cyp4a10 and not detectable with Cyp4a14. Cyp4a12a and Cyp4a12b also efficiently converted EPA (eicosapentaenoic acid) into 19/20-OH- and 17,18-epoxy-EPA. In male mice, renal microsomal AA hydroxylase activities ranged between approx. 100 (NMRI), 45-55 (FVB/N, 129 Sv/J and Balb/c) and 25 pmol x min(-1) x mg(-1) (C57BL/6). The activities correlated with differences in Cyp4a12a protein and mRNA levels. Treatment with 5alpha-dihydrotestosterone induced both 20-HETE production and Cyp4a12a expression more than 4-fold in male C57BL/6 mice. All female mice showed low AA hydroxylase activities (15-25 pmol x min(-1) x mg(-1)) and very low Cyp4a12a mRNA and protein levels, but high Cyp4a10 and Cyp4a14 expression. Renal Cyp4a12b mRNA expression was almost undetectable in both sexes of all strains. Thus Cyp4a12a is the predominant 20-HETE synthase in the mouse kidney. Cyp4a12a expression determines the sex- and strain-specific differences in 20-HETE generation and may explain sex and strain differences in the susceptibility to hypertension and target organ damage. << Less

  Biochem. J. 403:109-118(2007) [PubMed] [EuropePMC]

  This publication is cited by 13 other entries.

• Arachidonic and eicosapentaenoic acid metabolism by human CYP1A1: highly stereoselective formation of 17(R),18(S)-epoxyeicosatetraenoic acid.

  Schwarz D., Kisselev P., Ericksen S.S., Szklarz G.D., Chernogolov A., Honeck H., Schunck W.H., Roots I.

  Human cytochrome P450 1A1 (CYP1A1) and human NADPH-cytochrome P450 reductase were expressed and purified from Spodoptera frugiperda insect cells. A reconstituted enzymatically active system metabolized polyunsaturated fatty acids such as arachidonic (AA) and eicosapentaenoic acid (EPA). CYP1A1 was ... >> More

  Human cytochrome P450 1A1 (CYP1A1) and human NADPH-cytochrome P450 reductase were expressed and purified from Spodoptera frugiperda insect cells. A reconstituted enzymatically active system metabolized polyunsaturated fatty acids such as arachidonic (AA) and eicosapentaenoic acid (EPA). CYP1A1 was an AA hydroxylase which oxidizes this substrate at a rate of 650+/-10 pmol/min/nmol CYP1A1, with over 90% of metabolites accounted for by hydroxylation products and with 19-OH-AA as major product. Epoxyeicosatrienoic acid (EET), mainly 14,15-EET, accounted for about 7% of total metabolites. Unlike rat CYP1A1, the human enzyme exhibited no 20-OH-AA as product. In contrast, with EPA as substrate CYP1A1 was mainly an epoxygenase, oxidizing with over 68% of total metabolites EPA to 17(R),18(S)-epoxyeicosatetraenoic acid (17(R),18(S)-EETeTr). 19-OH-EPA accounted for about 31% of total metabolites. Significantly, the 17,18-olefinic bond of EPA was epoxidized to 17(R),18(S)-EETeTr with nearly absolute regio- and stereoselectivity. Molecular modeling analyses provided rationale for high efficiency of AA hydroxylation at C(19) and its gradual decrease down to C(14), as well as for the limited EPA 17(S),18(R) epoxidation due to unfavorable enzyme-substrate interactions. The absence of omega-hydroxylation for both substrates is not due to steric factors, but probably a consequence of different reactivities of omega and (omega-1) carbons for hydrogen abstraction. It is suggested that the capacity of human CYP1A1 to metabolize AA and EPA and its inducibility by polycyclic aromatic hydrocarbons may affect the production of physiologically active metabolites, in particular, in the cardiovascular system and other extrahepatic tissues including lung. << Less

  Biochem. Pharmacol. 67:1445-1457(2004) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.

• cDNA cloning and expression of CYP4F12, a novel human cytochrome P450.

  Bylund J., Bylund M., Oliw E.H.

  cDNA of a novel human cytochrome P450 was cloned from human liver by reverse transcription-polymerase chain reaction and designated CYP4F12. The open reading frame coded for 524 amino acids, and the sequence could be aligned with 78-83% amino acid identity to the four human CYP4F enzymes (CYP4F2, ... >> More

  cDNA of a novel human cytochrome P450 was cloned from human liver by reverse transcription-polymerase chain reaction and designated CYP4F12. The open reading frame coded for 524 amino acids, and the sequence could be aligned with 78-83% amino acid identity to the four human CYP4F enzymes (CYP4F2, CYP4F3, CYP4F8 and CYP4F11). Northern blot analysis suggested three major transcripts of CYP4F12, which were detected in liver, kidney, colon, small intestine and heart. The CYP4F12 gene contained 13 exons and was located at chromosome 19p13.1. CYP4F12, expressed in yeast, oxidized arachidonic acid to 18-hydroxyarachidonic acid, and the omega-side chain of two stable prostaglandin (PG) H(2) analogs (11,9-epoxymethano-PGH(2) and 9,11-diazo-15-deoxy-PGH(2)). CYP4F12 oxidized the omega-side chain of leukotriene B(4), PGE(2), PGF(2 alpha), PGH(2), and 9,11-epoxymethano-PGH(2) poorly. Several CYP4F enzymes are important omega 1- and omega 2-hydroxylases of eicosanoids. The physiological function of CYP4F12 merits further investigation. << Less

  Biochem. Biophys. Res. Commun. 280:892-897(2001) [PubMed] [EuropePMC]

• Cloning and expression of murine CYP2Cs and their ability to metabolize arachidonic acid.

  Luo G., Zeldin D.C., Blaisdell J.A., Hodgson E., Goldstein J.A.

  Five murine cytochrome P450 (CYP) 2C cDNAs were cloned and characterized, including four new members of this subfamily: CYP2C37, CYP2C38, CYP2C39, and CYP2C40. The cDNAs ranged from 1716 to 1812 bp in length and encoded polypeptides of 490 amino acid residues except for CYP2C40, which contained an ... >> More

  Five murine cytochrome P450 (CYP) 2C cDNAs were cloned and characterized, including four new members of this subfamily: CYP2C37, CYP2C38, CYP2C39, and CYP2C40. The cDNAs ranged from 1716 to 1812 bp in length and encoded polypeptides of 490 amino acid residues except for CYP2C40, which contained an additional glutamic acid residue at the carboxyl terminus. The amino acid identity of the murine CYP2Cs ranged from 69 to 92%, while the overall amino acid identity was 60%; however, within the six putative substrate recognition sites the identity was only 25 to 41%, suggesting possible differences in substrate specificity and product profiles. The CYP2C cDNAs were expressed in Escherichia coli following modification of the N-terminus. All five recombinant CYP2Cs metabolized arachidonic acid, but with different metabolic profiles and catalytic rates. Based on coelution with authentic standards on reverse-phase HPLC, themajor metabolites were tentatively identified asfollows: CYP2C29 and CYP2C39 produced 14, 15-cis-epoxyeicosatrienoic acid (EET); CYP2C37 produced 12-hydroxyeicosatetraenoic acid (HETE); CYP2C38 produced 11,12-EET; and CYP2C40 produced an unidentified metabolite that coeluted with 16-,17-, and 18-HETEs. The turnover numbers for CYP2C29, CYP2C37, CYP2C38, CYP2C39, and CYP2C40 were 0.34, 1.12, 5.15, 0.51, and 0.15 nmol/nmol/min, respectively. Reverse transcriptase-polymerase chain reaction demonstrated the presence of CYP2C29 mRNA in liver as well as in extrahepatic tissues including brain, kidney, lung, heart, and intestine. CYP2C38 and CYP2C40 were found in liver, brain, kidney, and intestine, with trace amounts in lung and heart, while CYP2C37 and CYP2C39 appeared to be liver specific. << Less

  Arch. Biochem. Biophys. 357:45-57(1998) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.