PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 16594688

Cytochrome p450 compound I.

Martin Newcomb·Rui Zhang·R Esala P Chandrasena·James A Halgrimson·John H Horner·Thomas M Makris·Stephen G Sligar
View original source ↗Export metadata ↓

Abstract

Cytochrome P450 enzymes (P450s) comprise a large class of enzymes that effect numerous oxidations in nature. The active oxidants in P450s are thought to be iron(IV)-oxo porphyrin radical cations termed Compounds I, and these intermediates have been sought since the discovery of P450s 40 years ago. We report formation of the Compound I derivative of a P450 enzyme by laser flash photolysis oxidation of the corresponding Compound II species, an iron(IV)-oxo neutral porphyrin intermediate. The Compound II derivative in turn was produced by oxidation of the P450 with peroxynitrite, which effected a net one-electron, oxo-transfer reaction to the iron(III) atom of the resting enzyme. For the P450 studied in this work, CYP119 from the thermophile Sulfolobus solfactaricus, the P450 Compound II derivative was stable for seconds at ambient temperature, and the Compound I transient decayed with a lifetime of ca. 200 ms.

Explore related subjects

Archaeal ProteinsCytochrome P-450 Enzyme SystemOxidation-ReductionOxygenasesPeroxynitrous AcidPhotochemistrySpectrum AnalysisSulfolobus solfataricusJournal ArticleResearch Support, N.I.H., Extramural

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Martin Newcomb, Rui Zhang, R Esala P Chandrasena, James A Halgrimson, John H Horner, Thomas M Makris, Stephen G Sligar. 2006-04-12. Cytochrome p450 compound I.. https://doi.org/10.1021/ja060048y

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

PF0610, a novel winged helix-turn-helix variant possessing a rubredoxin-like Zn ribbon motif from the hyperthermophilic archaeon, Pyrococcus furiosus.

PF0610, a protein from the hyperthermophile Pyrococcus furiosus, has homologues only in other archaeal species and in three species of Fe(III)-reducing bacteria. It is thought to have a helix-turn-helix (HTH) domain at the N-terminus and possesses two CXXC motifs characteristic of metal binding proteins. We have determined the solution structure of the Zn-bound protein using NMR. PF0610 is a novel winged helix-turn-helix (wHTH) protein with a rubredoxin-like Zn ribbon as its W1 segment. In addition, it possesses a large number of basic residues on its surface. Clusters of basic residues can be found on both helix H3 and the metal-binding loops of W1, suggesting that it might be a DNA-binding protein. Accordingly, gel shift assays using both linear and circular DNA showed that PF0610 does bind DNA, at least in a sequence-independent fashion. Modeling the PF0610-DNA interaction based on other wHTH protein-DNA structures revealed that besides helix H3, basic residues around the second CXXC motif in the metal-binding loop could make extensive contacts with DNA. However, the bulkiness of the W1 region implies that the DNA conformation may be distorted upon PF0610 binding. PF0610 is the first protein known to have a Zn ribbon-embedded wHTH fold and, as such, has potential roles both as a metal-dependent transcription regulator and as a component of the chromosome packing system in P. furiosus. The discovery of this novel structure represents the addition of another branch to the winged HTH protein family and could contribute to our understanding of transcription regulatory processes in P. furiosus.

Archaeal Proteins↗
PubMed2007

Enzymes and proteins from extremophiles as hyperstable probes in nanotechnology: the use of D-trehalose/D-maltose-binding protein from the hyperthermophilic archaeon Thermococcus litoralis for sugars monitoring.

The D-trehalose/D-maltose-binding protein (TMBP), a monomeric protein of 48 kDa, is one component of the trehalose and maltose (Mal) uptake system. In the hyperthermophilic archaeon Thermococcus litoralis, this is mediated by a protein-dependent ATP-binding cassette system transporter. The gene coding for a thermostable TMBP from the archaeon T. litoralis has been cloned, and the recombinant protein has been expressed in E. coli. The recombinant TMBP has been purified to homogeneity and characterized. It exhibits the same functional and structural properties as the native one. In fact, it is highly thermostable and binds sugars, such as maltose, trehalose and glucose, with high affinity. In this work, we have immobilized TMBP on a porous silicon wafer. The immobilization of TMBP to the chip was monitored by reflectivity and Fourier Transformed Infrared spectroscopy. Furthermore, we have tested the optical response of the protein-Chip complex to glucose binding. The obtained data suggest the use of this protein for the design of advanced optical non-consuming analyte biosensors for glucose detection.

Archaeal Proteins↗