Abstract:
:The aromatic hydroxylation of six pairs of selectively deuterated monosubstituted benzenes was investigated with rat liver microsomes of various induction states. The substrates studied included 3,5-D2C6H3X (1a-6a) and 2,4,6-D3C6H2X (1b-6b), where X = Br, CN, NO2, OCH3, CH3, or Ph, respectively. The deuterium content of the ortho, meta, and para hydroxylated metabolites, as well as side chain oxidation products from 4 and 5, was determined by capillary gas chromatography-mass spectroscopy. These data were analyzed according to a hypothetical model in which a molecule of substrate can undergo either direct aromatic hydroxylation (defined as obligatory and complete loss of deuterium from the site of hydroxylation) or indirect aromatic hydroxylation (defined as the obligatory and complete shift of deuterium to an adjacent position, followed by its partial loss as governed by a kinetic deuterium isotope effect). From this and other analyses of the data the following conclusions were reached. (1) The relative extent of meta hydroxylation increased and the total yield of metabolites decreased as the substituents X became more electron withdrawing. (2) The induction state of the microsomes altered the regioselectivity of hydroxylation (2, 3, 4, or side chain) noticeably and predictably but had little or no effect on the retention or loss of deuterium during each hydroxylation. (3) With each substrate and at each ring position hydroxylation was found to occur by a combination of direct and indirect mechanisms. (4) The relative importance of direct vs. indirect mechanisms did not vary in a simple manner with either the position of hydroxylation or the nature of the substituent X.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Hanzlik RP,Hogberg K,Judson CMdoi
10.1021/bi00308a031subject
Has Abstractpub_date
1984-06-19 00:00:00pages
3048-55issue
13eissn
0006-2960issn
1520-4995journal_volume
23pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The fatty acid acylated insulin, Lys(B29)-tetradecanoyl, des-(B30) human insulin, has been crystallized and the structure determined by X-ray crystallography. The fatty acid substituent on residue B29 Lys binds reversibly to circulating albumin protein in vivo, and by this mechanism the hormone's action is prolonged. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9625105
更新日期:1997-03-11 00:00:00
abstract::PQQ is an exogenous, tricyclic, quino-cofactor for a number of bacterial dehydrogenases. The final step of PQQ formation is catalyzed by PqqC, a cofactorless oxidase. This study focuses on the activation of molecular oxygen in an enzyme active site without metal or cofactor and has identified a specific oxygen binding...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1015474
更新日期:2011-03-08 00:00:00
abstract::In the cytochrome P450cam-dependent monooxygenase system from Pseudomonas putida, putidaredoxin (Pdx) shuttles electrons between putidaredoxin reductase (Pdr) and P450cam and, thus, must form transient complexes with both partners. 1-Ethyl 3-[3-(dimethylamino)propyl]carbodiimide (EDC) was found to promote formation of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901872s
更新日期:2010-01-12 00:00:00
abstract::The distances between the anticodon loops of fluorescent tRNAPhe bound to the E site and to either the A or the P site of poly(U)-programmed Escherichia coli ribosomes were measured by fluorescence energy transfer. Donor and acceptor molecules were wybutine and proflavin, respectively, both located 3' to the anticodon...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00358a002
更新日期:1986-05-20 00:00:00
abstract::Aminoimidazole riobnucleotide carboxylase, the sixth step in the purine biosynthetic pathway, catalyzes the conversion of aminoimidazole ribonucleotide (AIR) to carboxyaminoimidazole ribonucleotide (CAIR). The gene products of the purE and purK genes (PurE and PurK, respectively) thought to be responsible for this act...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00136a016
更新日期:1992-06-02 00:00:00
abstract::The structure of the subgel phase of dipalmitoylphosphatidylglycerol (DPPG) has been analyzed by X-ray diffraction techniques. Diffraction recorded from highly oriented DPPG specimens in the subgel phase extends to 2-A resolution. There are sharp lamellar reflections on the meridian, and other reflections lie on a ser...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00350a003
更新日期:1986-01-28 00:00:00
abstract::The NikR transcription factor from Escherichia coli is a Ni(II)-dependent repressor that regulates production of the nickel ion transporter encoded by the nik operon. In the previous paper in this issue (Wang, S. C., Dias, A., Bloom, S. L., and Zamble, D. B. (2004) Selectivity of Metal Binding and Metal-Induced Stabil...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049404k
更新日期:2004-08-10 00:00:00
abstract::Despite much work, subcellular neurons of Caenorhabditis elegans have not been studied at nanometer resolution with millisecond time resolution. Nor has there been an effective way to immobilize C. elegans. Here we show that, without using anesthetic or paralyzing agents, fluorescence imaging with one-nanometer accura...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi8023477
更新日期:2009-06-09 00:00:00
abstract::The mechanism of chromophore biosynthesis in green fluorescent protein (GFP) is triggered by a spontaneous main chain cyclization reaction of residues 65-67. Here, we demonstrate that the initially colorless Y66L variant, designed to trap chromophore precursor states, is oxidatively modified to generate yellow chromop...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0503798
更新日期:2005-06-14 00:00:00
abstract::Reaction of 1-oxiranylpyrene (1-OP) with DNA and the structures of the covalent and noncovalent complexes formed were studied in aqueous media (5 mM phosphate buffer with 0.1 M NaCl, pH 7) by utilizing the techniques of absorption, fluorescence and linear dichroism spectroscopy in order to gain an understanding of pos...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00318a009
更新日期:1984-11-06 00:00:00
abstract::To test the prediction that extensively fluorinated (fluorous) proteins should be more stable and exhibit novel self-segregating behavior, the properties of the de novo designed model 4-alpha-helix bundle protein, alpha 4F 6, in which the hydrophobic core is packed entirely with the extensively fluorinated amino acid ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi702476f
更新日期:2008-04-15 00:00:00
abstract::Calcium and its receptor protein calmodulin function in the regulation of proliferation of mammalian cells. A 68 kDa calmodulin-specific binding protein was shown previously to be associated with growth factor-dependent progression of a variety of mammalian cells from G1 to S phase and to stimulate DNA synthesis in pe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00012a002
更新日期:1995-03-28 00:00:00
abstract::Extensive studies of the physiological protein-protein electron-transfer (ET) complex between yeast cytochrome c peroxidase (CcP) and cytochrome c (Cc) have left unresolved questions about how formation and dissociation of binary and ternary complexes influence ET. We probe this issue through a study of the photocycle...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500888y
更新日期:2015-02-10 00:00:00
abstract::DnaB helicase is responsible for unwinding duplex DNA during chromosomal DNA replication and is an essential component of the DNA replication apparatus in Escherichia coli. We have analyzed the mechanism of binding of single-stranded DNA (ssDNA) by the DnaB x DnaC complex and DnaB helicase. Binding of ssDNA to DnaB he...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060118d
更新日期:2006-09-26 00:00:00
abstract::We have prepared the following cadmium-113-substituted derivatives of bovine superoxide dismutase and recorded the nuclear magnetic resonance (NMR) spectrum of the cadmium: 2Cd(II), in which Cd(II) is presumed to bind to the Zn(II) site and the copper site is unoccupied, and 2Cd(II)--2Cu(I), which is analogous to the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00544a031
更新日期:1980-02-05 00:00:00
abstract::The present study focuses on ligand-protein interactions in a rhodopsin analogue generated from bovine opsin and the 10-methyl homologue of 11-cis-retinal. The analogue pigment displays a reduced alpha-band at 506 +/- 2 and a stronger beta-band at 325 nm. Remarkably, the rotational strength of these bands observed in ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972397y
更新日期:1998-02-03 00:00:00
abstract::Steric constraints in the retinal binding pocket of sensory rhodopsin I (SR-I) are analyzed by studying effects of sample temperature and retinal analogs. The flash-induced yield of the earliest detected intermediate S610, which corresponds to the K intermediate in the bacteriorhodopsin (BR) photocycle, decreases belo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00089a044
更新日期:1993-09-28 00:00:00
abstract::To probe the motional and conformational properties of the choline head group of 1,2-dipalmitoyl-sn-glycero-3-thiophosphocholine (DPPsC), the Rp, Sp, and Rp + Sp isomers of [alpha-D2]DPPsC, [beta-D2]DPPsC, and [delta-D9]DPPsC in the subgel, gel, and liquid crystalline phases were investigated with deuterium NMR, and t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00501a008
更新日期:1990-12-11 00:00:00
abstract::We studied the interactions between the SH2 domain of growth factor receptor binding protein 2 (Grb2) and ErbB receptor-derived phosphotyrosyl peptides using molecular dynamics, free energy calculations, and surface plasmon resonance (SPR) analysis. Binding free energies for nine phosphotyrosyl peptides were calculate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034113h
更新日期:2003-05-13 00:00:00
abstract::Islet-activating protein (IAP), pertussis toxin, is a hexameric protein composed of an A protomer and a B oligomer, the residual pentamer having such a subunit assembly that two different dimers, dimer 1 and dimer 2, are connected with each other by means of the smallest C subunit. Incubation of IAP with formaldehyde ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00354a025
更新日期:1986-03-25 00:00:00
abstract::A procedure for universal 13C and/or 15N labeling of microbial peptides which are produced by fermentation in complex media and its application to two food-preserving bacteriocins from lactic acid bacteria are described. Isotopic enrichment of nisin A (from Lactococcus lactis) and of leucocin A (from Leuconostoc gelid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00052a039
更新日期:1993-01-12 00:00:00
abstract::Hybridization experiments with variants of an oligomeric protein often provide important information regarding subunit structure, function, and interactions. In some systems, however, the variants are so similar electrophoretically and chromatographically that purification of individual hybrids is not feasible. Theref...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00646a009
更新日期:1976-01-13 00:00:00
abstract::Conformational distributions of a four-way DNA junction have been examined by time-resolved fluorescence resonance energy transfer (FRET). A series of dye-labeled junctions were synthesized with donor (fluorescein) and acceptor (tetramethylrhodamine) dyes conjugated to the 5' termini of the duplex arms in all six pair...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00213a014
更新日期:1993-12-21 00:00:00
abstract::[1-Penicillamine,2-leucine]oxytocin is a conformationally restricted analogue of oxytoxin in which the half-cystine-1 and tyrosine-2 residues of the native hormone are replaced by half-penicillamine (beta, beta-dimethyl-half-cystine) and leucine, respectively. This analogue is a surprisingly potent oxytocin antagonist...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00513a018
更新日期:1981-05-12 00:00:00
abstract::A 19-amino acid residue peptide, Gly-Trp-Leu-Lys-Ile-Lys-Ala-Ala-Met-Arg-Trp-Gly-Phe-Phe-Val-Arg-Lys-Lys- Ala, corresponding to the basic amphiphilic alpha-helix (BAA) motif at the C-terminus of a recombinant tobacco calmodulin-binding protein, TCB60, was synthesized. The interaction of the synthetic binding domain wi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9621674
更新日期:1997-02-25 00:00:00
abstract::Azurin from Pseudomonas aeruginosa and two mutants where the methionine ligand has been mutated have been studied in order to directly investigate the functional and structural significance of this ligand in the blue copper proteins. Reduction potentials, X-ray absorption fine structure (XAFS), electron paramagnetic r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00059a013
更新日期:1993-03-02 00:00:00
abstract::Inducible dimers are powerful tools for controlling biological processes through colocalizing signaling molecules. To be effective, an inducible system should have a dissociation constant in the "off" state that is greater (i.e., weaker affinity) than the concentrations of the molecules that are being controlled, and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00529
更新日期:2016-09-20 00:00:00
abstract::Circular dichroism (CD) spectra at variable temperatures have been recorded for human cytosolic sialidase NEU2 in buffered water solutions and in the presence of divalent cations. The results show the prevalence of β-strands together with a considerable amount of α-helical structure, while in the solid state, from bot...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500249r
更新日期:2014-08-19 00:00:00
abstract::Experimental measurements of the kinetic mechanism involving isoleucyl-tRNA synthetase proofreading valyl-tRNAIle in Escherichia coli have been incorporated into the conventional Michaelis-Menten model for this system. The model was subjected to a detailed mathematical analysis in the steady state. The results of this...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00303a019
更新日期:1984-04-10 00:00:00
abstract::Redox transitions in the Rhodobacter capsulatus cytochrome bc(1) complex were investigated by perfusion-induced attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy combined with synchronous visible spectroscopy, in both the wild type and a cytochrome c(1) point mutant, M183K, in which the mi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049211x
更新日期:2004-07-27 00:00:00