Cytochrome mammalian

Like the a2ole derivatives, it inhibits the biosynthesis of ergosterol. However, naftifine [65472-88-0] does not inhibit the cytochrome P-450 dependent C-14-demethylase, but the epoxidation of squalene. Squalene epoxidase cataly2es the first step in the conversion of squalene via lanosterol to ergosterol in yeasts and fungi or to cholesterol in mammalian cells. The squalene epoxidase in C. albicans is 150 times more sensitive to naftifine, C2 H2 N, than the en2yme in rat fiver (15). Naftifine is available as a 1% cream. 

Furthermore, as shown in Figure 5.28, the number of amino acid differences between two cytochrome c sequences is proportional to the phylogenetic difference between the species from which they are derived. The cytochrome c in humans and in chimpanzees is identical human and another mammalian (sheep) cytochrome c differ at 10 residues. The human cytochrome c sequence has 14 variant residues from a reptile sequence (rattlesnake), 18 from a fish (carp), 29 from a mollusc (snail), 31 from an insect (moth), and more than 40 from yeast or higher plants (cauliflower). 

Mammalian sulfite oxidase is the last enzyme in the pathway for degradation of sulfur-containing amino acids. Sulfite oxidase (SO) catalyzes the oxidation of sulfite (SO ) to sulfate (S04 ), using the heme-containing protein, cytochrome c, as electron acceptor ... 

Fergu.son-Miller, S., 1996. Mammalian cytochrome coxida.se, a molecular mon.ster subdued. Science 272 1125. 

Two main apoptotic pathways have been identified in mammalian cells the extrinsic pathway that is activated by the binding of ligands to cell-surface death receptors, and the intrinsic pathway that involves the mitochondrial release of cytochrome cP The activation of extrinsic and intrinsic apoptotic pathways promotes the cleavage into the active form of the pro-caspase-8 and pro-caspase-9, respectively, that mainly determine the activation of effector caspase-3. ° The intrinsic pathway is the main apoptotic pathway activated by chemotherapeutic drugs, while the cytotoxic drug-induced activation of the extrinsic pathway is a more controversial issue. ... 

Barlow, GH Margoliash, E, Electrophoretic Behavior of Mammalian-Type Cytochromes c. The Journal of Biological Chemistry 241, 1473, 1966. 

Lewis DFV. Qn the recognition of mammalian microsomal cytochrome P450 substrates and their characteristics. Biochem Pharmacol 2000 60 293-306. 

Williams PA, Cosme J, Sridhar V, Johnson EF, McRee DE. Mammalian microsomal cytochrome P450 monooxygenase structural adaptations for membrane binding and functional diversity. Mol Cell 2000 5 121-31. 

Szklarz GD, Halpert JR. Use of homology modeling in conjunction with site-directed mutagenesis for analysis of structure-function relationships of mammalian cytochromes P450. Life Sci 1997 61 2507-20. 

Szklarz GD, Graham SE, Paulsen MD. Molecular modeling of mammalian cytochromes P450 application to study enzyme function. Vitamins Hormones 2000 58 53-87. 

Mammalian cytochrome P450 2E1 was introduced into tobacco plants that were exposed to trichloroethene in hydroponic medium for 5 d. Trichloroethene epoxide was produced initially, and was rearranged to trichloroacetaldehyde, which was then reduced to trichloro-ethanol. This was found in samples of leaves, stems, and roots, but was absent in the control plants. Trichloroethanol was subsequently transported to the leaves where it was apparently metabolized (Doty et al. 2000). 

Goodacre, R. Karim, A. Kaderbhai, M. A. Kell, D. B. Rapid and quantitative analysis of recombinant protein expression using pyrolysis mass spectrometry and artificial neural networks Application to mammalian cytochrome b5 in Escherichia coli. J. Biotechnol. 1994,34,185-193. 

As noted with the chemotaxonomic studies, the limited resolving power and mass accuracy of MALDI-TOF complicates identification of unknown proteins. If the greatly improved resolving power and accuracy of MALDI-FTMS can be used to monitor overexpressed proteins, it could have significant advantages. Figure 13.12 is a MALDI-FTMS spectrum of E. coli whole cells that have been genetically altered to produce the soluble core domain mammalian cytochrome b5 protein, which consists of 98 amino acids. 

Patten, C.J., Ishizaki, H., Aoyama, T. et al. (1992) Catalytic properties of the human cytochrome P450 2E1 produced by cDNA expression in mammalian cells. Archives of Biochemistry and Biophysics, 299 (1), 163-171. 

Hubl, U. and Stevenson, D.E. (2001) In vitro enzymic synthesis of mammalian liver xenobiotic metabolites catalyzed by ovine liver microsomal cytochrome P450. Enzyme and Microbial Technology, 29, 306-311. 

WRF presents an intracellular enzymatic system, cytochrome P450 monooxigenases, similar to those mammalian cells, that catalyzes a broad range of intracellular degradation reactions of released metabolites after the pollutants breaking by extracellular enzymes. 

This chapter describes some of the modified mammalian cell-based systems that have been developed to express intestinal cytochrome P450 enzymes and intestinal transporters. The reader should be aware that other experimental systems, such as transporter expression and drug uptake studies in Xenopus laevis oocytes, have also shown considerable promise [1],... 

Gardner et al. [165] have shown that the redox-cycling agent phenazine methosulfate (PMS), mitochondrial ubiquinol-cytochrome c oxidoreductase, or hypoxia inactivated aco-nitase in mammalian cells. It has been proposed that the inactivation of aconitase is mediated by superoxide produced by prooxidants because the overproduction of mitochondrial MnSOD protected aconitase from inactivation by the prooxidants mentioned above except hyperoxia. Later on, the reaction of superoxide with aconitases began to be considered as one of the most important ways to NTBI generation in vivo. 

The postmitochondrial events of apoptosis include activation of the caspases. Cytochrome c binds to the protein Apaf-1 in the cytosol, resulting in the recruitment and activation of caspase-9, which in turn activates cas-pase-3 (Figs 35-4, 35-5). Fourteen different mammalian caspases have been identified and each may play a key role... 

Chapter 6). Other iron-sulfur proteins, so named because they contain iron sulfur clusters of various sizes, include the rubredoxins and ferredoxins. Rubredoxins are found in anaerobic bacteria and contain iron ligated to four cysteine sulfurs. Ferredoxins are found in plant chloroplasts and mammalian tissue and contain spin-coupled [2Fe-2S] clusters. Cytochromes comprise several large classes of electron transfer metalloproteins widespread in nature. At least four cytochromes are involved in the mitrochondrial electron transfer chain, which reduces oxygen to water according to equation 1.29. Further discussion of these proteins can be found in Chapters 6 and 7 of reference 13. 

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