Cytochrome enzymology

Structure and Enzymology of Diheme Enzymes Cytochrome cdy Nitrate and Cytochrome c Peroxidase Vilmos Fiilop, Nicholas J. Watmough, and Stuart J. Ferguson... 

Correia, M.A. (1991) Cytochrome P450 turnover. Methods in Enzymology, 206, 315-325. 

STRUCTURE AND ENZYMOLOGY OF TWO BACTERIAL DIHEME ENZYMES CYTOCHROME cd NITRITE REDUCTASE AND CYTOCHROME c PEROXIDASE... 

Jefcoate, C.R. (1978) Measurement of substrate and inhibitor binding to microsomal cytochrome P-450 by optical-difference spectroscopy. Methods in Enzymology, 52, 258—279. 

D Silva PD, Schilke B, Walter W, Andrew A, Craig EA (2003) J protein cochaperone of the mitochondrial inner membrane required for protein import into the mitochondrial matrix. Proc Natl Acad Sci USA 100 13839-13844 Dalbey RE, Lively MO, Bran S, van Dijl JM (1997) The chemistry and enzymology of the type I signal peptidases. Protein Sci 6 1129-1138 Daley DO, Clifton R, Whelan J (2002) Intracellular gene transfer reduced hydrophobicity facilitates gene transfer for subunit 2 of cytochrome c oxidase. Proc Natl Acad Sci USA 99 10510-10515... 

Makris TM, Davydov R, Denisov IG, et al. Mechanistic enzymology of oxygen activation by the cytochromes p450. Drug Metab Rev 2002 34 691-708. 

Wedlund PJ, Wilkinson GR. In vivo and in vitro measurement of CYP2C19 activity. In Johnson EF, Waterman MR, eds. Cytochrome P450, Part B Methods in Enzymology. San Diego Academic Press, 1996 272 105-114. 

McGinnity DF, Parker AJ, Soars M, Riley RJ (2000) Automated definition of the enzymology of drug oxidation by the major human drug metabolizing cytochrome P450s. Drug Metab Dispos 28 1327-1334... 

Goldstein, J. A., and Blaisdell, J. Genetic tests which identify the principle defects in CYP2C19 responsible for the polymorphism in mephenytoin metabolism. In Johnson, E.F., and Waterman, M. R. (Eds.). Methods in Enzymology, Vol. 272, Cytochrome P450, Part B, Academic Press, San Diego, CA, 1996, pp. 210-217. 

This chapter will review the general features of the enzymology of methanol dehydrogenase, its structure as determined by X-ray crystallography, the properties of the prosthetic group (PQQ), the mechanism of its reduction by substrate, its oxidation by its specific cytochrome electron acceptor, and processes involved in its synthesis. 

The search for an enzyme activity was successful, and a reasonably pure flavoprotein, NADPH-cytochrome c reductase (EC 1.6.2.4), was isolated from yeast (15). It was then 1940, and basic research was interrupted and not taken up again until the end of the Second World War. During that interval, Horecker worked on war-related programs, was appointed to the staff of the National Institutes of Health, and in 1945 returned to basic research in enzymology. He proceeded to isolate NADPH-cytochrome c reductase from acetone-dried extracts of pig liver (16), at a time that was almost coincident with the report of Lehninger (10) that... 

Members of the Sulfolobaceae (Sulfolobus and Acidianus) are facultative heterotrophs that can oxidize hydrogen sulfide to elemental sulfur and the latter to sulfuric acid. Nothing is known about the enzymology of these processes and to what extent membrane-boimd enzymes are involved. What information there is relates to the electron transport system of Sulfolobus which is relatively simple consisting as it does of dehydrogenases for succinate and NADH, a quinone pool, a complex of b-cytochromes, and several oxidases. 

Fig. 8. Difference spectra of the three spinach cytochromes isolated by imposing appropriate redox potentials In the sample and reference. See text for details. Figure source DS Bendall, HE Davenport and R Hill (1974) Cytochrome components of the higher plants. Methods in Enzymology 23 341.

For several years, she studied chemical reaction mechanisms, especially those involving sulfoxide carbanions and their synthetic applications. Then, she turned to mechanistic enzymology. Her main interests concerned steroid isomerases and cytochrome P-450, vitamin K-dependent carboxylations, and biotin biosynthesis. She contributed to the mechanistic understanding of several enzymes of the pathway, namely, amino-oxopelargo-nate synthase, diaminopelargonate aminotransferase, and more importantly biotin synthase. 

Enzymology and Stoichiometry A depiction of the thermodynamic analysis of substrate, P450, and NADPH cytochrome P450 reductase interactions is shown in Figure 8.13. 

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