Functional differences in the cytochrome P450 1 family enzymes from Zebrafish ( Danio rerio) using heterologously expressed proteins

• Published in: Archives of biochemistry and biophysics Vol. 502; no. 1; pp. 17 - 22
• Main Authors: Scornaienchi, Marcus L., Thornton, Cammi, Willett, Kristine L., Wilson, Joanna Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2010
• Subjects: Animals; Benzo(a)pyrene - metabolism; Cloning, Molecular; CYP1 family; Cytochrome P-450 Enzyme System - classification; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P450; Danio rerio; Expression system; Fluorescent Dyes; Freshwater; Kinetics; Oxazines - metabolism; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Substrate Specificity; Zebrafish; Zebrafish - genetics; Zebrafish - metabolism; Zebrafish Proteins - classification; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism; Expression system; Zebrafish; CYP1 family; Cytochrome P450; Substrate specificity
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2010.06.018

Mammalian cytochrome P450 1 (CYP1) genes are well characterized, but in other vertebrates only the functions of CYP1A genes have been well studied. We determined the catalytic activity of zebrafish CYP1A, CYP1B1, CYP1C1, CYP1C2, and CYP1D1 proteins using 11 fluorometric substrates and benzo[a]pyrene (BaP). The resorufin-based substrates, 7-ethoxyresorufin, 7-methoxyresorufin, and 7-benzyloxyresorufin, were well metabolized by all CYP1s except CYP1D1. CYP1A metabolized nearly all substrates tested, although rates for non-resorufin substrates were typically lower than resorufin-based substrates. Zebrafish CYP1s did not metabolize 7-benzyloxyquinoline, 3-[2-( N, N-diethyl- N-methylamino)ethyl]-7-methoxy-4-methylcoumarin or 7-methoxy-4-(aminomethyl)-coumarin. CYP1B1 and CYP1C2 had the highest rates of BaP metabolism. 3-Hydroxy-BaP was a prominent metabolite for all but CYP1D1. CYP1A showed broad specificity and had the highest metabolic rates for nearly all substrates. CYP1C1 and CYP1C2 had similar substrate specificity. CYP1D1 had very low activities for all substrates except BaP, and a different regioselectivity for BaP, suggesting that CYP1D1 function may be different from other CYP1s. ► Resorufin based substrates (ER, MR, BR) are well metabolized by CYP1s except CYP1D1. ► CYP1A had broad metabolic specificity. ► CYP1A had the highest catalytic rate for nearly all substrates. ► CYP1D1 had very low activities for nearly all substrates. ► CYP1D1 had a different regioselectivity for BaP.