Cytochromes, structure-function

Lewis, D.F.V. (1996). Cytochromes P450 Structure Function and Mechanism. Taylor and Francis London. 

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. 

Lewis, D. V. F. (1996) Cytochrome P450 structure, function and mechanism. Taylor and Francis, London. 

Tween 85 is used extensively for RME [84]. Russell and coworkers [234] used Tween 85/isopropanol microemulsions in hexane to solubilize proteins and not only showed >80% solubilization of cytochrome C at optimum conditions, but also proved that Tween 85 does not have a detrimental effect on the structure, function, and stability of subtilisin and cytochrome C. There are other reports available on the extraction and purification of proteins using Tween 85-RMs and also on the stability of protein activity in these systems [234]. It has also been shown that Tween 85-RMs can solubilize larger amounts of protein and water than AOT. Tween 85 has an HLB of 11, which indicates that it is soluble in organic solvents. In addition, it is biodegradable and can be successfully used as an additive in fertihzers [235,236]. Pfammatter et al. [35] have demonstrated that RMs made of Tween 85 and Span 80 can be successfully used for the solubilization and growth of whole cells. Recently, Hossain et al. [84] showed an enhanced enzymatic activity of Chromobacterium viscosum Hpase in AOT/Tween 85 mixed reverse micellar systems when compared to that in classical AOT-RMs. This is due to the modification of the interface in AOT-RMs caused by the co-adsorption of Tween 85, and increased availability of the oHve oil molecules (substrate) to the enzyme. 

Correia MA Human and rat liver cytochromes P450 Functional markers, diagnostic inhibitor probes and parameters frequently used in P450 studies. In Ortiz de Montellano P (editor). Cytochrome P450 Structure, Mechanism and Biochemistry, 3rd ed. Kluwer-Academic/Plenum Press, 2005. 

A. J. Bearden, W. R. Durnham Iron Electronic Configurations in Proteins Studies by Moss-bauer Spectroscopy. - K Wiitkrich Structural Studies of Hemes and Hemoproteins by Nuclear Magnetic Resonance Spectroscopy. -H. A 0. Hill,A. Roder, R. J. P. Williams The Chemical Nature and Reactivity of Cytochrome P-450. - S. Lindskog Cobalt (II) in Metalloenzymes. A Reporter of Structure-Function Relations. 

Sundaramoorthy M, Temer J, Poulos TL (1995) The Crystal Structure of Chloroperoxidase A Heme Peroxidase-Cytochrome P450 Functional Hybrid. Structure 3 1367... 

Ortiz de Montellano, P. R. De Voss, J. J.In Cytochrome P450 Structure, Function, Genetics, 3rd edition Ortiz de Montellano, P. R.,Ed. Kluwer Academic/Plenum Publishers New York, 2005 pp. 183-245. 

Domanski TL, Schultz KM, Roussel F, et al. Structure-function analysis of human cytochrome P-4502B6 using a novel substrate, site-directed mutagenesis, and molecular modeling. J Pharmacol Exp Ther 1999 290 1141-1147. 

Graham-Lorence S, Khalil MW, Lorence MC, et al. Structure-function relationships of human aromatase cytochrome P-450 using molecular modeling and site-directed mutagenesis. J Biol Chem 1991 266 11939-11946. 

Lewis DFV. Cytochromes P450 - Structure, Function and Mechanism. London Taylor Francis, 1996. 

Black SD, Coon MJ. P-450 cytochromes structure and function. Adv Enzymol 60 35-75, 1987. 

De Smet L, Sawides SN, Van Horen E et al (2006) Structural and mutagenesis studies on the cytochrome c peroxidase from Rhodobacter capsulatus provide new insights into structure-function relationships of bacterial di-heme peroxidases. J Biol Chem 281 4371 1379... 

Tegoni, M., White, S. A., Roussel, A., Mathews, F. S., and Cambillau, C., 1993, A hypothetical complex between crystalline flavocytochrome bi and cytochrome c. Proteins Structure, Function, and Genetics 16 4089422... 

Paulsen, M. D., and Omstein, R. L., 1995, Dramatic differences in the motions of the mouth of open and closed cytochrome P450 BM3 by molecular dynamics simulations. Proteins Structure, Function and Genetics 21 2379243. 

There are several types of nitrite reduetion reaetion in biology and the use of the eommon name initrite reductasei for the enzymes eatalysing these reactions causes endless confusion. Thus we begin this article by outlining the different types and functions of the nitrite reductases before focusing on the structure/function relationships for one type of enzyme, cytochrome cdi nitrite reductase. 

Tron, T., Crimi, M., Colson, A. M., and Degli Esposti, M., 1991, Structure/function relationships in mitochondrial cytochrome b revealed by the kinetic and circular dichroic properties of two yeast inhibitor-resistant mutants, Eur. J. Biochem. 199 753n760. 

Amino acid sequence analysis and determination of subunit composition are painstaking but these steps are usually necessary before further structural investigations are undertaken. It should not be forgotten that chemical composition and amino acid sequencing provided a foundation for recent structure-function findings in the cytochrome oxidase field. The complete amino acid sequence and a successful prediction of the number of a-helices greatly contributed to the successful and rapid crystallographic analysis of bovine heart cytochrome c oxidase at 2.8 resolution, four years ago (Tsukihara et al., 1995 Tsukihara et al., 1996). 

Halkier, B.A. (1996) Catalytic reactivities and structure/function relationships of cytochrome P450 enzymes. Phytochemistry, 43,1-21. 

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