Cytochrome biocatalysis

Garcia-Arellano, H. Valderrama, B. Saab-Rincon, G., and Vazquez-Duhalt, R., High Temperature Biocatalysis by Chemically Modified Cytochrome c. Bioconjugate Chem. 2002. 13 pp. 1336-1344. 

Garcia-Arellano H, Valderrama B, Saab-Rincon G et al (2002) High temperature biocatalysis by chemically modified cytochrome c. Bioconjug Chem 13 1336-1344... 

More in particular, cytochrome c can be dissolved in choline dihydrogenphosphate, containing 10-20% of water, up to final concentration of 37 mg/ml. Very significantly, tlie secondary structure of the enzyme is retained in the IL solubilized protein, and the thermal stability increases. The nature of the anion seems to be fundamental for the application in biocatalysis the... 

In suimnaiy, cytochrome P450 monooxygenases have a number of advantages for biocatalysis ... 

Lamb SB, Lamb DC, Kelly SL, Stuekey DC (1998) Cytochrome P450 immobilisation as a route to bio-remediation/biocatalysis. FEBS Lett 431 343 346... 

Mayhew MP, Reipa V, Holden MJ, Vilker VL (2000) Improving the cytochrome P450 enzyme system for electrode-driven biocatalysis of styrene epoxidation. Biotechnol Prog 16 610-616... 

Holtmann D, Mangold KM, Schrader J (2009) Entrapment of cytochrome P450 BM-3 in polypyrrole for electrochemically-driven biocatalysis. Biotechnol Lett 31 765-770... 

An emerging field of biocatalysis is the enzymatic nitration of arene substrates. In 2012, it was reported that TxtE (a cytochrome P450) catalyzed the nitration of L-Trp at the indole 4-position during the biosynthesis of thaxtomin A [102]. It was further determined that the source of nitrogen... 

Homogeneous biocatalysis in both fluorous biphasic and supercritical CO systems has been demonstrated [6]. By forming protein-surfactant complexes by hydrophobic ion pairing with a highly fluorinated anionic surfactant cytochrome c can be solubilized in perfluoromethylcyclohexane (PMFC) and in scCO. The secondary structure of the proteins within these ion-paired complexes has been shown to remain intact, and particle size analysis indicated that small aggregates of protein molecules surrounded by surfactant molecules are formed. The presence of the KDP (perfluoropolyether carboxylate surfactants) ion paired with a-chymotrypsin appears to enhance its catal)4ic activity as compared to that of the native enzyme in a fluorous biphasic system. The facile recycling of the a-chymotrypsin-KDP complex in a fluorous biphasic system has been demonstrated with retention of enzyme artivity over four reaction cycles. 

Modified electrodes for biocatalysis use either electron mediators or promoters immobilized on the electrode surface -. In both cases, redox enzyme molecules are in solution and in contact with the common electron mediators for redox enzymes such as cytochrome c and ferredoxin. An electron promoter is not a mediator since it does not take part in electron transfer in the potential region of interest. An electrode modified with promoter molecules has enables some redox enzymes to directly transfer electrons. It has been shown that 4,4 -bipyridyl, bis(4-pyridyl)sulfide, and bis 4-pyridyl)disulfide are excellent promoters of electron transfer of cytochrome c. Cytochrome c gives a reversible cyclic voltammogram at gold electrodes modified with these promoters. 

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