Abstract:
:1-Bromovinyl (I), Z-2-bromovinyl (II), 1,2-dibromoethyl (III), and a series of 4-(halomethyl)-2-nitrophenyl (IVa-c) diethyl phosphate esters were examined as substrates and mechanism-based inhibitors for the bacterial phosphotriesterase. All of these compounds were found to act as substrates for the enzyme. Inhibitor I rapidly inactivated the enzyme within 1 min, giving a partition ratio of 230. The newly formed covalent adduct with inhibitor I was susceptible to hydrolysis at elevated values of pH and dissociation by NH2OH. Azide was not able to protect the enzyme from inactivation with inhibitor I, implying that the reactive species was not released into solution prior to the inactivation event. The reactive species was proposed to be either an acyl bromide or a ketene intermediate formed by the enzymatic hydrolysis of inhibitor I. Compounds II and III were shown to be relatively poor substrates of phosphotriesterase and they did not induce any significant inactivation of the enzyme. The inhibitor, 4-(bromomethyl)-2-nitrophenyl diethyl phosphate (IVa), was found to irreversibly inactivate the enzyme with a KI = 7.9 mM and kinact = 1. 2 min-1 at pH 9.0. There was no effect on the rate of inactivation upon the addition of the exogenous nucleophiles, azide, and NH2OH. The species responsible for the covalent modification of the enzyme by IVa was most likely a quinone methide formed by the elimination of bromide from the phenolic intermediate. NMR experiments demonstrated that the quinone methide did not accumulate in solution. The chloro (IVb) and fluoro (IVc) analogues did not inactivate the enzyme. These results suggest that the elimination of the halide ion from the phenolic intermediate largely determines the partition ratio for inactivation.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Hong SB,Mullins LS,Shim H,Raushel FMdoi
10.1021/bi970680rsubject
Has Abstractpub_date
1997-07-22 00:00:00pages
9022-8issue
29eissn
0006-2960issn
1520-4995pii
bi970680rjournal_volume
36pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Using solution peptide synthesis, we have made three series of N alpha-formylated homooligopeptides, from the dipeptide to the heptapeptide, derived from L-methionine, L-norleucine, and S-methyl-L-cysteine and related to the chemotactic peptide N alpha-formylmethionylleucylphenylalanine. Compounds were prepared to det...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00299a018
更新日期:1984-02-14 00:00:00
abstract::The l-lyxonate dehydratase (LyxD) in vitro enzymatic activity and in vivo metabolic function were assigned to members of an isofunctional family within the mandelate racemase (MR) subgroup of the enolase superfamily. This study combined in vitro and in vivo data to confirm that the dehydration of l-lyxonate is the bio...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi5004298
更新日期:2014-05-27 00:00:00
abstract::The relaxin-like factor (RLF) is a circulating hormone that is synthesized in the gonads of mammals and released into the bloodstream. The distribution of its receptor and a trace of cross-reactivity to relaxin receptors implied that this relatively new factor is more relaxin- than insulin-like. The chemical synthesis...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982687u
更新日期:1999-03-09 00:00:00
abstract::Plasmids containing a site-specifically incorporated O6-methyl- (m6G), O6-ethyl- (e6G), or O6-benzylguanine (b6G) within the ATG initiation codon of the lacZ' gene were used to transform Escherichia coli that were repair proficient or deficient in one or both of the E. coli O6-alkylguanine-DNA alkyltransferases, the u...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00197a020
更新日期:1994-08-09 00:00:00
abstract::The covalent modification of chicken liver fatty acid synthase by 4-(1-pyrenyl)butyryl-CoA (PBA-CoA), a fluorescent analogue of acetyl- and malonyl-CoA, has been studied. The binding isotherms and the kinetics of inactivation suggest 2 mol of PBA-CoA/mol of enzyme is specifically incorporated into the enzyme. Two clas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00281a032
更新日期:1983-06-07 00:00:00
abstract::We review signaling by reactive oxygen species, which is emerging as a major physiological process. However, among the reactive oxygen species, H(2)O(2) best fulfills the requirements of being a second messenger. Its enzymatic production and degradation, along with the requirements for the oxidation of thiols by H(2)O...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi9020378
更新日期:2010-02-09 00:00:00
abstract::Cellular toxicity resulting from nucleation-dependent polymerization of amyloid beta-peptide (Abeta) is considered to be a major and possibly the primary component of Alzheimer's disease (AD). Inhibition of Abeta polymerization has thus been identified as a target for the development of therapeutic agents for the trea...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982824n
更新日期:1999-05-25 00:00:00
abstract::We describe the synthesis of bordifluoropyrromethene (BODIPY), fluorescein, and related fluorescent derivatives of the beta-adrenergic ligand CGP 12177. With these probes we screened insect (Sf9) cells stably transformed with the human beta 2-adrenoceptor gene and expressing (2-3.5) x 10(5) human beta 2-adrenoceptors ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00197a015
更新日期:1994-08-09 00:00:00
abstract::Oligonucleotides labeled with hexachlorofluorescein (hex) have enabled the interaction of the restriction endonuclease EcoRV with DNA to be evaluated using fluorescence anisotropy. The sensitivity of hex allowed measurements at oligonucleotide concentrations as low as 1 nM, enabling K(D) values in the low nanomolar ra...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001956p
更新日期:2001-02-27 00:00:00
abstract::Peptidylglycine alpha-hydroxylating monooxygenase (PHM) is a copper, ascorbate, and molecular oxygen dependent enzyme that catalyzes the first step leading to the C-terminal amidation of glycine-extended peptides. The catalytic core of PHM (PHMcc), refined to residues 42-356 of the PHM protein, was expressed at high l...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9708747
更新日期:1997-09-09 00:00:00
abstract::Protein disulfide isomerase (PDI) utilizes the active site sequence Cys-Gly-His-Cys (CGHC; E degrees ' = -180 mV) to effect thiol-disulfide interchange during oxidative protein folding. Here, the Cys-Gly-Cys-NH(2) (CGC) peptide is shown to have a disulfide reduction potential (E degrees ' = -167 mV) that is close to t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026993q
更新日期:2003-05-13 00:00:00
abstract::Many bacteria produce isonitrile-containing natural products that are derived from aromatic amino acids. The synthetic clusters that control biosynthesis most commonly encode two enzymes, designated PvcA and PvcB, as well as additional enzymes that direct synthesis of the natural product. The PvcA enzyme installs the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00255
更新日期:2015-04-28 00:00:00
abstract::The three-dimensional solution structure of the repeating -PO4-6Gal beta 1-4Man alpha 1- disaccharide fragment of the lipophosphoglycan (LPG) derived from Leishmania donovani has been determined by use of a combination of homo- and heteronuclear NMR spin coupling constant measurements together with restrained molecula...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00118a004
更新日期:1992-01-28 00:00:00
abstract::Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a monotopic membrane protein anchored to the membrane by an N-terminal in-plane amphipathic alpha-helix. This membrane anchor is essential for the assembly of a functional viral replication complex. Although amino acid sequences differ considerably, putative m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0517685
更新日期:2006-02-21 00:00:00
abstract::Sucrose density gradient shift assays were used to study the interactions of human glucocorticoid receptors (GR) with small DNA fragments either containing or lacking glucocorticoid response element (GRE) DNA consensus sequences. When crude cytoplasmic extracts containing [3H]triamcinolone acetonide [( 3H]TA) labeled ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00431a003
更新日期:1989-03-07 00:00:00
abstract::Onconase (ONC) from Rana pipiens is the smallest member of the ribonuclease A (RNase A) superfamily. Despite a tertiary structure similar to RNase A, ONC is distinguished by an extremely high thermodynamic stability. In the present paper we have probed the significance of three structural regions, which exhibit struct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0525223
更新日期:2006-03-21 00:00:00
abstract::An alanine racemase encoded by a gene from the thermophilic Gram-positive bacterium Bacillus stearothermophilus is overproduced to 0.3% of the soluble protein when carried on plasmid pICR4 in Escherichia coli [Inagaki, K., Tanizawa, K., Badet, B., Walsh, C. T., Tanaka, H., & Soda, K. (1986) Biochemistry (third paper o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00359a029
更新日期:1986-06-03 00:00:00
abstract::Glycosylation is a common modification that can endow proteins with altered physical and biological properties. Ribonuclease 1 (RNase 1), which is the human homologue of the archetypal enzyme RNase A, undergoes N-linked glycosylation at asparagine residues 34, 76, and 88. We have produced the three individual glycofor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00191
更新日期:2020-09-01 00:00:00
abstract::Proteogenomic identification of translated small open reading frames in humans has revealed thousands of microproteins, or polypeptides of fewer than 100 amino acids, that were previously invisible to geneticists. Hundreds of microproteins have been shown to be essential for cell growth and proliferation, and many reg...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00672
更新日期:2020-10-27 00:00:00
abstract::Human DNA polymerase kappa (pol kappa) has a sequence significantly homologous with that of Escherichia coli DNA polymerase IV (pol IV). We used a truncated form of human pol kappa (pol kappaDeltaC) and full-length pol IV to explore the miscoding properties of these enzymes. Oligodeoxynucleotides, modified site-specif...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010702g
更新日期:2001-12-18 00:00:00
abstract::The solution structure of the C-terminal fragment 255-316 of thermolysin has been determined by two-dimensional proton NMR methods. For this disulfide-free fragment there was a previous proposal according to which it would fold into a stable helical structure forming a dimer at concentrations above 0.06 mM. A complete...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00253a023
更新日期:1994-12-13 00:00:00
abstract::Alkalimetric, spectrophotometric, NMR, and resonance Raman titrations are reported for the sulfonamide Neoprontosil in aqueous solution. An assignment of the magnetic resonance peaks for each of the Neoprontosil protons has been made. Neoprontosil is shown to have two "coupled" iity of the microscopic pKs for these tw...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00580a024
更新日期:1979-06-26 00:00:00
abstract::Upon cleavage of the reactive thioester bonds (Cys-949-Glx-952) of tetrameric human alpha 2-macroglobulin (alpha 2M) by methylamine, one sulfhydryl group per alpha 2M subunit is exposed. These identical sulfhydryl group sites were labeled with the thiol-specific nitroxide spin-labels (1-oxy-2,2,5,5-tetramethyl-3-pyrro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00414a053
更新日期:1988-07-12 00:00:00
abstract::We detect internal water molecules in a membrane-embedded receptor-transducer complex and demonstrate water structure changes during formation of the signaling state. Time-resolved FTIR spectroscopy reveals stimulus-induced repositioning of one or more structurally active water molecules to a significantly more hydrop...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi802180a
更新日期:2009-02-10 00:00:00
abstract::Cumene hydroperoxide-mediated (CuOOH-mediated) inactivation of cytochromes P450 (CYPs) results in destruction of their prosthetic heme to reactive fragments that irreversibly bind to the protein. We have attempted to characterize this process structurally, using purified, 14C-heme labeled, recombinant human liver P450...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9808464
更新日期:1998-12-15 00:00:00
abstract::The relative roles of insulin and glucose in the regulation of hepatic glycogen synthase and phosphorylase were studied in hepatocytes from fed rats. Elevation of extra-cellular glucose led to a rapid decrease in phosphorylase a activity followed by a slower increase in glycogen synthase I activity. A reciprocal and c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00596a004
更新日期:1978-02-07 00:00:00
abstract::The effects of various ginsenosides on calmodulin-dependent phosphodiesterase isozymes have been investigated. Ginsenosides were found to be potent inhibitors of bovine heart calmodulin-dependent phosphodiesterase and the 60-kDa isozyme of bovine brain calmodulin-dependent phosphodiesterase but not of the 63-kDa isozy...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00070a001
更新日期:1993-05-18 00:00:00
abstract::A simple procedure is introduced for accurately defining the precision with which the Cartesian coordinates of any macromolecular structure are determined by nuclear Overhauser data. The method utilizes an ensemble of structures obtained from an array of independent simulated data sets derived from a final structure. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00057a027
更新日期:1993-02-16 00:00:00
abstract::The dependence of the activity of recombinant activated human protein C (r-APC) on each of its nine gamma-carboxyglutamic (Gla) residues (sequence positions 6, 7, 14, 16, 19, 20, 25, 26, and 29) has been assessed in purified systems and in plasma using r-mutants in which each Gla residue of r-APC was individually alte...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00173a033
更新日期:1994-02-22 00:00:00
abstract::Fluorescent and photoactivatable fluorescent derivatives of tetrodotoxin (TTX) have been synthesized. N-Methylanthraniloylglycine hydrazide, anthraniloyl hydrazide, and 2-azidoanthraniloylglycine hydrazide were coupled to the carbonyl at C6 of oxidized tetrodotoxin to form stable fluorescent hydrazones. The C6 ketone ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00517a025
更新日期:1981-07-07 00:00:00