Abstract:
:The orientation of eukaryotic cytochromes P450, with respect to the membrane of the endoplasmic reticulum, has been investigated. There is now good evidence that the tertiary structure of these proteins is essentially the same as that of the soluble bacterial isoenzyme cytochrome P450CI, with the exception of an extension at the N-terminus which is thought to form a membrane-anchoring sequence. The remainder of the molecule protrudes from the cytosolic face of the membrane so that it can interact with substrates and electron-donating proteins. Two models based on this structure have been considered, in which the plane of the heme of cytochrome P450 is oriented either parallel with or perpendicular to the plane of the membrane of the endoplasmic reticulum. The validity of these models has been assessed from the results of studies involving the binding of antipeptide antibodies directed toward known regions of cytochromes P450, modeling of the interaction of cytochrome P450 with cytochrome b5, proposed intramolecular movements of cytochrome P450 during its catalytic cycle, and the partitioning of substrates for cytochrome P450 between the cytosol and membrane. It is concluded that cytochrome P450 is most likely oriented such that the heme is not fixed horizontal to the plane of the membrane of the endoplasmic reticulum and may well lie with the heme perpendicular to the membrane.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Edwards RJ,Murray BP,Singleton AM,Boobis ARdoi
10.1021/bi00215a011subject
Has Abstractpub_date
1991-01-08 00:00:00pages
71-6issue
1eissn
0006-2960issn
1520-4995journal_volume
30pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The catalytically competent active-site structure of a true acylenzyme reaction intermediate of TEM-1 beta-lactamase formed with the kinetically specific spin-labeled substrate 6-N-(2,2,5,5-tetramethyl-1-oxypyrrolinyl-3-carboxyl)-penicillanic acid isolated under cryoenzymologic conditions has been determined by angle-...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0021075
更新日期:2001-02-27 00:00:00
abstract::The preferential interactions of proteins with solvent components were studied in concentrated aqueous solutions of the sulfate, acetate, and chloride salts of Mg2+, Ba2+, Ca2+, Mn2+ and Ni2+ [except for CaSO4, BaSO4, Mn-(OAc)2, and Ni(OAc)2], and results were compared with those of the Na+ salts. It was found that, f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00320a004
更新日期:1984-12-04 00:00:00
abstract::The cytochrome bc(1) complex from Paracoccus denitrificans and soluble fragments of its cytochrome c(1) and Rieske ISP subunits are characterized by a combined approach of protein electrochemistry and FTIR difference spectroscopy. The FTIR difference spectra provide information about alterations in the protein upon re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035103j
更新日期:2003-10-28 00:00:00
abstract::Inwardly rectifying potassium channels are important in cellular repolarization of many excitable tissues. Amino acid sequence alignment of different mammalian inward rectifier K(+) channels revealed two absolutely conserved cysteine residues in the putative extracellular face, suggesting a possible disulfide bond. Re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992469g
更新日期:2000-04-25 00:00:00
abstract::The complete amino acid sequence was determined for bovine ubiquitin, and adenylate cyclase stimulating polypeptide, which is probably represented universally in living cells. Ubiquitin has a molecular weight of 8451 and consists of a single polypeptide chain containing 74 amino acid residues. It contains four argini...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00681a026
更新日期:1975-05-20 00:00:00
abstract::An oligodeoxynucleotide containing four thymines and covalently attached to an acridine derivative through its 3'-phosphate [(Tp)4(CH2)5Acr] was synthesized. Its conformation in solution was investigated by proton magnetic resonance. Both intramolecular interactions between the acridine dye and thymines and intermolec...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00331a019
更新日期:1985-05-07 00:00:00
abstract::The high molecular weight folate binding protein of rat liver cytosol has been purified to apparent homogeneity. Purification was achieved by using a combination of gel filtration, O-(diethylaminoethyl)cellulose chromatography, and affinity chromatography. This folate binding protein was initially identified during pu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00261a036
更新日期:1982-08-31 00:00:00
abstract::The nonconvertible substrate analogues di-, tri-, and tetramethylammonium are bound with fairly high affinity to oxidized methylamine dehydrogenase (MADHox) from Thiobacillus versutus and induce the same red-shift in the optical absorbance spectrum of MADHox as do the monovalent cations Cs+, Rb+, and NH4+. Like the mo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00040a002
更新日期:1995-10-10 00:00:00
abstract::DrrA and DrrB proteins form an ATP-dependent efflux pump for doxorubicin and daunorubicin in Streptomyces peucetius. DrrA, the catalytic subunit, forms a complex with the integral membrane protein DrrB. Previous studies have provided evidence for strong interaction between these two proteins, which was found to be cri...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701699a
更新日期:2008-03-04 00:00:00
abstract::We developed a general strategy for labeling expressed membrane proteins with a peptide epitope tag and detecting the tagged proteins in native cellular membranes. First, we genetically encoded the unnatural amino acid p-azido-L-phenylalanine (azF) at various specific sites in a G protein-coupled receptor (GPCR), C-C ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi301292h
更新日期:2013-02-12 00:00:00
abstract::Polyisoprenyl diphosphates play diverse and vital roles in cell function in health and disease. The counter-regulatory lipid signaling molecule, presqualene diphosphate (PSDP), is rapidly converted to its monophosphate form (PSMP) upon cell activation [Levy, B. D., Petasis, N. A., and Serhan, C. N. (1997) Nature 389, ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi8020636
更新日期:2009-04-07 00:00:00
abstract::Thiazolinyl imine reductases catalyze the NADPH-dependent reduction of a thiazoline to a thiazolidine, a required step in the formation of the siderophores yersiniabactin (Yersinia spp.) and pyochelin (Pseudomonas aeruginosa). These stand-alone nonribosomal peptide tailoring domains are structural homologues of sugar ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00735
更新日期:2016-09-27 00:00:00
abstract::The transferrins (TFs) are a family of proteins that are widely distributed in vertebrates, where they serve a major role in iron binding and transport. Most TFs are composed of two homologous lobes, the N- and C-lobes, each able to bind a single iron atom. Human serum transferrin (hTF) binds iron in the blood and del...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi027071q
更新日期:2003-04-08 00:00:00
abstract::Class II tRNA synthetases have long been known to have quaternary structures of alpha, alpha2, alpha2beta2, and alpha4, depending on the amino acid specificity and the organism from which the synthetase was isolated. Even the quaternary structures of enzymes for the same amino acid show variations in evolution. The ba...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971788+
更新日期:1997-12-09 00:00:00
abstract::Porcine aortic myosin is a smooth muscle contractile protein similar to its striated muscle counterpart. Electrophoresis in sodium dodecyl sulfate indicates that the molecule consists of three classes of subunits with polypeptide chain molecular weights of 192,000, 19,000, and 15,000. At 277 nm the absorption spectrum...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00576a003
更新日期:1979-05-01 00:00:00
abstract::Yeast mitochondrial NAD+-specific isocitrate dehydrogenase (IDH) has previously been shown to bind specifically to 5'-untranslated regions of yeast mitochondrial mRNAs, and transcripts containing these regions have been found to allosterically inhibit activity of the enzyme. This inhibition is relieved by AMP, an allo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0200662
更新日期:2002-06-04 00:00:00
abstract::Non-heme diiron clusters occur in a number of enzymes (e.g., ribonucleotide reductase, methane monooxygenase, and Delta9-stearoyl-ACP desaturase) that activate O2 for chemically difficult oxidation reactions. In each case, a kinetically labile peroxo intermediate is believed to form when O2 reacts with the diferrous e...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981838q
更新日期:1998-10-20 00:00:00
abstract::The primary electron acceptor pheophytin (Pheo(D1)) plays a crucial role in regulation of forward and backward electron transfer in photosystem II (PSII). It is known that some cyanobacteria control the Pheo(D1) potential in high-light acclimation by exchanging the D1 proteins from different copies of the psbA genes. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9018829
更新日期:2010-01-26 00:00:00
abstract::A quartz-crystal microbalance (QCM) technique was applied to analyze effects of site-directed mutagenesis of a glycosidase (isomalto-dextranase) on the hydrolysis mechanism of the substrate binding (k(on), k(off), and K(d)) and the catalytic process (k(cat)), separately, by using a dextran-immobilized QCM in buffer so...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050079q
更新日期:2005-07-12 00:00:00
abstract::Ca2+-induced fusion of phospholipid vesicles (phosphatidylcholine/phosphatidic acid, 9:1 mol/mol) prepared by ethanolic injection was followed by five different procedures: resonance energy transfer, light scattering, electron microscopy, intermixing of aqueous content, and gel filtration through Sepharose 4-B. The fi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00329a015
更新日期:1985-04-09 00:00:00
abstract::Long-chain alkanols are general anesthetics which can also act as uncharged noncompetitive inhibitors of the peripheral nicotinic acetylcholine receptor (AChR) by binding to one or more specific sites on the AChR. Cembranoids are naturally occurring, uncharged noncompetitive inhibitors of peripheral and neuronal AChRs...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0112255
更新日期:2001-09-18 00:00:00
abstract::Intrastrand cross-links (IaCL) connecting two purine nucleobases in DNA pose a challenge to high-fidelity replication in the cell. Various repair pathways or polymerase bypass can cope with these lesions. The influence of the phosphodiester linkage between two neighboring 2'-deoxyguanosine (dG) residues attached throu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01078
更新日期:2015-12-29 00:00:00
abstract::Light-induced GTP-dependent scattering changes are studied in suspensions of retinal disc membranes to which one or both of the purified proteins involved in the phototransduction mechanism (G-protein and cGMP phosphodiesterase) are reassociated; a scattering change which depends on the presence of both G-protein (G) ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00121a039
更新日期:1992-02-18 00:00:00
abstract::We studied the basic steps of proton transfer through ATP synthase of chloroplasts, CF0CF1, under conditions of proton slip, a conducting stage in the absence of added nucleotides. On the background of a steady transmembrane pH difference, voltage steps were induced by flashing light. Proton intake, transfer, and rele...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00027a008
更新日期:1995-07-11 00:00:00
abstract::Matrix metalloproteinases (MMPs) are a family of enzymes that are up-regulated in many diseases, including osteoarthritis (OA) and rheumatoid arthritis (RA). Here we report on a novel technique that can be used to simultaneously measure activity levels for a panel of enzymes, such as the MMPs. The technique, termed th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi036063m
更新日期:2004-03-23 00:00:00
abstract::The removal of damaged bases by DNA glycosylases is thought to be effectively irreversible, because of an overall equilibrium that favors hydrolysis over synthesis of the N-glycosyl bond. Surprisingly, human alkyladenine DNA glycosylase (AAG) can make damaged DNA by catalyzing formation of an N-glycosyl bond between 1...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101380d
更新日期:2010-10-26 00:00:00
abstract::Choline oxidase catalyzes the oxidation of choline to glycine betaine through a two-step, four-electron reaction with betaine aldehyde as an intermediate. Oxygen is the final electron acceptor. Alcohol oxidation is initiated by the removal of the substrate hydroxyl proton by an unknown active site residue with a pKa v...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500982y
更新日期:2015-01-20 00:00:00
abstract::As a light-driven water-plastoquinone oxidoreductase, Photosystem II produces molecular oxygen as an enzymatic product. Additionally, under a variety of stress conditions, reactive oxygen species are produced at or near the active site for oxygen evolution. In this study, Fourier-transform ion cyclotron resonance mass...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300650n
更新日期:2012-08-14 00:00:00
abstract::The human, cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) reversibly converts isocitrate to α-ketoglutarate (αKG). Cancer-associated somatic mutations in IDH1 result in a loss of this normal function but a gain in a new or neomorphic ability to convert αKG to the oncometabolite 2-hydroxyglutarate (2HG). To improve...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400514k
更新日期:2013-07-02 00:00:00
abstract::Nicotinic acid phosphoribosyltransferase (NAPRTase; EC 2.4.2.11) forms nicotinic acid mononucleotide (NAMN) and PPi from 5-phosphoribosyl 1-pyrophosphate (PRPP) and nicotinic acid (NA). The Vmax NAMN synthesis activity of the Salmonella typhimurium enzyme is stimulated about 10-fold by ATP, which, when present, is hyd...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9720134
更新日期:1998-03-24 00:00:00