cytochromes

Antimycin A4 is an active component of the antimycin A antibiotic complex that is more polar than antimycin A1 , antimycin A2 , and antimycin A3 . Antimycin A4 inhibits ATP-citrate lyase with a Ki value of 64.8 μM. The antimycin A complex is a mixture of antimycins A1, A2, A3, and A4 that demonstrates antifungal, insecticidal, nematocidal, and piscicidal properties. It blocks mitochondrial respiration and can deplete cellular levels of ATP via inhibition of complex III of the mitochondrial electron transport chain (ETC). Antimycin A prevents the transfer of electrons between the b-cytochromes and ubiquinone at the Q(inner) site of complex III. This results in the stabilization of the ubisemiquinone radical at the Q(outer) site of complex III, leading to increased production of superoxide. Antimycin A is widely used in research to shunt electron flow through the ETC to study the chemical details of oxygen respiration. Additionally, antimycin A has been shown to inhibit Bcl-2 and Bcl-xL proteins, inducing apoptosis.

14S(15R)-EET is an oxylipin and a cytochrome P450 metabolite of arachidonic acid .114S(15R)-EET binds to isolated guinea pig monocytes with a Kivalue of 612.5 nM in a competitive binding assay using [3H]14(15)-EET.2It induces dilation of precontracted isolated canine epicardial arterioles (EC50= 4 pM) and denuded porcine subepicardial arterioles (EC50= 3 pM).3Unlike 14R(15S)-EET, 14S(15R)-EET does not inhibit COX in enzyme assays or isolated platelets.4 1.Daikh, B.E., Lasker, J.M., Raucy, J.L., et al.Regio- and stereoselective epoxidation of arachidonic acid by human cytochromes P450 2C8 and 2C91J. Pharmacol. Exp. Ther.271(3)1427-1433(1994) 2.Wong, P.Y.-K., Lai, P.-S., and Falck, J.R.Mechanism and signal transduction of 14 (R), 15 (S)-epoxyeicosatrienoic acid (14,15-EET) binding in guinea pig monocytesProstaglandins Other Lipid Mediat.62(4)321-333(2000) 3.Zhang, Y., Oltman, C.L., Lu, T., et al.EET homologs potently dilate coronary microvessels and activate BKCa channelsAm. J. Physiol. Heart Circ. Physiol.280(6)H2430-H2440(2001) 4.Fitzpatrick, F.A., Ennis, M.D., Baze, M.E., et al.Inhibition of cyclooxygenase activity and platelet aggregation by epoxyeicosatrienoic acidsJ. Biol. Chem.261(2)15334-15338(1986)

16α-hydroxy Dehydroepiandrosterone is a metabolite of the endogenous steroid hormone dehydroepiandrosterone .116α-hydroxy Dehydroepiandrosterone is formed from dehydroepiandrosteronevia16-hydroxylation by the cytochrome P450 (CYP) isoforms CYP3A4 and CYP3A5 in adult human liver microsomes, as well as by fetal recombinant CYP3A7. It is a precursor to fetal estrogens, including estriol .2 1.Miller, K.K.M., Cai, J., Ripp, S.L., et al.Stereo- and regioselectivity account for the diversity of dehydroepiandrosterone (DHEA) metabolites produced by liver microsomal cytochromes P450Drug. Metab. Dispos.32(3)305-313(2004) 2.Hampl, R., and Starka, L.Minireview: 16α-Hydroxylated metabolites of dehydroepiandrosterone and their biological significanceEndocr. Regul.34(3)161-163(2000)

1-Ethynylpyrene is an aryl acetylenic inhibitor of CYTP450 1A1(IC50=0.18 μM), 1A2(IC50 = 0.32 μM), and 2B1(IC50 = 0.04 μM).

Cytochrome c fragment (93-108) is a peptide from Cytochrome c, which is a small heme protein found loosely associated with the inner membrane of the mitochondrion. Cytochromes c from certain eukaryotes, including plants and fungi but not higher animals, contains methylated lysine residues at specific positions1. Cytochrome c is a required cofactor for Apaf-1 function2.

Azoxystrobin (Bankit) is a broad-spectrum fungicide. Azoxystrobin induces ROS production, cell apoptosis and mitochondrial respiration by blocking electron transfer between cytochromes b and c1.

19R(20S)-EpDPA is an oxylipin and a metabolite of docosahexaenoic acid .1,2It is formed from DHA by various cytochrome P450 (CYP) isoforms in a stereoselective manner.219R(20S)-EpDPA (30 nM) prevents calcium-induced increases in the spontaneous beating of isolated neonatal rat cardiomyocytes (NRCMs).3 1.Cinelli, M.A., Yang, J., Scharmen, A., et al.Enzymatic synthesis and chemical inversion provide both enantiomers of bioactive epoxydocosapentaenoic acidsJ. Lipid Res.59(11)2237-2252(2018) 2.Lucas, D., Goulitquer, S., Marienhagen, J., et al.Stereoselective epoxidation of the last double bond of polyunsaturated fatty acids by human cytochromes P450J. Lipid Res.51(5)1125-1133(2010) 3.Burke, J.E., and Dennis, E.A.Phospholipase A2 structure/function, mechanism, and signalingJ. Lipid Res.50(Suppl)S237-S242(2009)

Cytochrome P450 CYP1B1 (190-198) [Homo sapiens] is a peptide from Cytochrome c, which is a small heme protein found loosely associated with the inner membrane of the mitochondrion. Cytochromes c from certain eukaryotes, including plants and fungi but not higher animals, contains methylated lysine residues at specific positions1. Cytochrome c is a required cofactor for Apaf-1 function2.