Functional differences between peroxidase compound I and the cytochrome P-450 reactive oxygen intermediate.

McCarthy, Mary-Beth; White, Ronald E.

doi:10.1016/s0021-9258(17)44644-8

Cited by 146 publications

(25 citation statements)

References 15 publications

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“…22 This rate is even faster than that of the biological system, ∼9 cycles/min. 23 Moreover, addition of a lipophilic carboxylic acid (benzoic acid) accelerated the rate of catalytic hydroxylation of cycloalkanes up to 125 cycles/min at 0 °C with up to 700 turnovers using a 5c-H 2 O 2 system, 24 a significant improvement from our original 5b-PFIB system.…”

Section: Introductionmentioning

confidence: 84%

Polyhaloporphyrins: Unusual Ligands for Metals and Metal-Catalyzed Oxidations

1997

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3) This paper as originally submitted to the Editor cited more than 100 references, which occupied fully one-third of the paper. In order to meet the space criteria of Accounts, we have chosen, where possible, to cite only recent references. A recent monograph gives an excellent up-to-date review of many areas touched upon here. Cytochrome P-450: Structure, Mechanism and Biochemistry, 2nd ed.; Ortiz de Montellano, P. R., Ed.; Plenum Press: New York, 1995. (4) Even the trivial names of porphyrins are frequently complex. In this review the major porphyrins are abbreviated as follows: TPP ) mesotetraphenylporphyrin (2a) etc. as shown for structures 2-14.Teddy G. Traylor (1925Traylor ( -1993 never graduated from high school, but after the war, where he served in the Merchant Marine, he received his Ph.D. at UCLA with Saul Winstein and then was a postdoctoral fellow with Paul Bartlett at Harvard. He was the first organic chemist hired at UCSD, where he was a pioneer in organometallic chemistry. Teddy was the first to publish papers on superstructured porphyrins, and his research on oxygen binding and P-450 chemistry was seminal for the past two decades. His love of chemistry was surpassed only by his love of life. We are sorry that he is not with us to still enjoy them. David Dolphin was born in London, England, at the beginning of the Second World War. After obtaining his undergraduate and graduate degrees at the University of Nottingham, he was a postdoctoral fellow with R. B. Woodward at Harvard and then joined the faculty there in 1966. In 1973 he joined the University of British Columbia, where he has been acting Dean of Science and is the NSERC/ QLT Industrial Research Professor in Photodynamic Technology. He is also the V.P. of Technology Development at QLT PhotoTherapeutics, a Vancouver-based biotechnology company that is the world leader in photodynamic therapy. Lily Y. Xie was born in Chongqing, People's Republic of China. She received her B.Sc. degree at Peking University in 1983 and her Ph.D. in 1990 at the University of British Columbia (UBC) under the direction of Brian R. James. She worked as a postdoctoral fellow with David Dolphin at UBC and then with Alison Butler at the

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Section: Introductionmentioning

confidence: 84%

Polyhaloporphyrins: Unusual Ligands for Metals and Metal-Catalyzed Oxidations

1997

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“…On the other hand, evidence against the involvement of a thiolate-ligated oxo−ferryl porphyrin π-cation radical intermediate in the P450 reaction cycle also exists. White compared the oxidative reactivity of several P450 enzymes with that of peroxidase enzymes and concluded that if both enzyme mechanisms involve an oxo−ferryl intermediate, then these species are somehow very different in both their mode of formation and reactivity . Characterization of the active oxygen intermediate in the P450 reaction cycle remains one of the most challenging areas of P450 research.…”

Section: Analogy To Chloroperoxidase Compound Imentioning

confidence: 99%

Heme-Containing Oxygenases

et al. 1996

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“…Although P450-catalyzed hydroxylations of hydrocarbons and the mechanism of this process have been widely studied, relatively few such studies have been performed with CPO. The first involved the hydroxylation of cyclohexene (10), and the others studied the hydroxylation of benzylic positions in substrates (11,12). One mechanistic study of CPO hydroxylation, reported in a paper focusing mainly on the use of CPO for stereoselective olefin epoxidations, resulted in the conclusion that this hydroxylation reaction involves an insertion process which occurs without the formation of a discrete radical intermediate (11).…”

Section: Introductionmentioning

confidence: 99%

Hypersensitive Radical Probe Studies of Chloroperoxidase-Catalyzed Hydroxylation Reactions

Toy

Newcomb

Hager

1998

Chem. Res. Toxicol.

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The oxidation of hypersensitive radical probes by chloroperoxidase from Caldariomyces fumago (CPO) was studied in an attempt to "time" a putative radical intermediate. Oxidation of (trans-2-phenylcyclopropyl)methane, previously studied by Zaks and Dodds [Zaks, A., and Dodds, D. R. (1995) J. Am. Chem. Soc. 115, 10419-10424] was reinvestigated. Unrearranged oxidation products were found as previously reported, and control experiments demonstrated that the cyclic alcohol from oxidation at the cyclopropylcarbinyl position, while subject to further oxidation, survives CPO oxidation as detectable species. However, in contrast to the report by Zaks and Dodds, the rearranged alcohol product expected from ring opening of a cyclopropylcarbinyl radical intermediate was shown to be unstable toward the enzyme oxidation reaction. Because of this instability, two new hypersensitive radical probes, (trans-2-phenylcyclopropyl)ethane and 2-(trans-2-phenylcyclopropyl)propane, and their potential cyclic and acyclic products from oxidation at the cyclopropylcarbinyl position were synthesized and tested. Oxidation of both of these probes at the cyclopropylcarbinyl position by CPO gave unrearranged alcohol products only, but control experiments again demonstrated that the rearranged alcohol products were unstable toward CPO oxidation conditions. From the combination of the probe and control studies, the lifetime of a putative radical intermediate must be less than 3 ps. Whereas the results are consistent with an insertion mechanism for production of alcohol product, they do not exclude a very short-lived intermediate.

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Functional differences between peroxidase compound I and the cytochrome P-450 reactive oxygen intermediate.

Cited by 146 publications

References 15 publications

Polyhaloporphyrins: Unusual Ligands for Metals and Metal-Catalyzed Oxidations

Polyhaloporphyrins: Unusual Ligands for Metals and Metal-Catalyzed Oxidations

Heme-Containing Oxygenases

Hypersensitive Radical Probe Studies of Chloroperoxidase-Catalyzed Hydroxylation Reactions

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