Abstract：
:An investigation into the kinetics and regulatory properties of the type-1 phosphofructokinase (PFK) from the extreme thermophile Thermus thermophilus (TtPFK) reveals an enzyme that is inhibited by PEP and activated by ADP by modifying the affinity exhibited for the substrate fructose 6-phosphate (Fru-6-P) in a manner analogous to other prokaryotic PFKs. However, TtPFK binds both of these allosteric ligands significantly more tightly than other bacterial PFKs while effecting a substantially more modest extent of inhibition or activation at 25 °C, reinforcing the principle that binding affinity and effectiveness can be both independent and uncorrelated to one another. These properties have allowed us to establish rigorously that PEP only inhibits by antagonizing the binding of Fru-6-P and not by influencing turnover, a conclusion that requires kcat to be determined under conditions in which both inhibitor and substrate are saturating simultaneously. In addition, the temperature dependence of the allosteric effects on Fru-6-P binding indicate that the coupling free energies are entropy-dominated, as observed previously for PFK from Bacillus stearothermophilus but not for PFK from Escherichia coli , supporting the hypothesis that entropy-dominated allosteric effects may be a characteristic of enzymes derived from thermostable organisms. For such enzymes, the root cause of the allosteric effect may not be easily discerned from static structural information such as that obtained from X-ray crystallography.
journal_name
Biochemistryjournal_title
Biochemistryauthors
McGresham MS,Lovingshimer M,Reinhart GDdoi
10.1021/bi401402jsubject
Has Abstractpub_date
2014-01-14 00:00:00pages
270-8issue
1eissn
0006-2960issn
1520-4995journal_volume
53pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:Streptomyces griseus trypsin has been isolated from Pronase by ion-exchange chromatography on CM-Sephadex and SE-Sephadex. The isolated enzyme was homogeneous by the criteria tested except for a low degree of contamination by an enzyme with nontryptic activity. The latter could be partially resolved by chromatography ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00677a010
更新日期：1975-03-25 00:00:00
abstract：:Electrophilic halogenating agents, including hypohalous acids and haloamines, oxidize free methionine and the N-terminal methionines of peptides and proteins (e.g., Met-1 of anti-inflammatory peptide 1 and ubiquitin) to produce dehydromethionine (a five-membered isothiazolidinium heterocycle). Amide derivatives of met...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi901343d
更新日期：2009-11-24 00:00:00
abstract：:Two bands of 5.8S rRNA were observed when the total RNA isolated from rat or mouse tissue was separated by electrophoresis on high-resolution polyacrylamide gels under denaturing conditions. The minor form, with a lower mobility, represented 15-35% of the total 5.8S rRNA, depending on the source of the tissue. Sequenc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00311a011
更新日期：1984-07-31 00:00:00
abstract：:The dark reaction of tris(hydroxymethyl)aminomethane (Tris) with the O2-evolving center of photosystem II (PSII) in the S1 state causes irreversible inhibition of O2 evolution. Similar inhibition is observed for several other amines: NH3, CH3NH2, (CH3)2NH, ethanolamine, and 2-amino-2-ethyl-1,3-propanediol. In PSII mem...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00246a003
更新日期：1991-08-13 00:00:00
abstract：:Chicken liver phosphoenolpyruvate carboxykinase (PEPCK) was rapidly inactivated by micromolar concentrations of ferrous sulfate in the presence of ascorbate at pH 7.4. Omitting ascorbate or replacing the Fe2+ with Mn2+ or Mg2+ gives no inactivation. Mn2+, Mg2+, or Co2+ at 100-fold molar excess over Fe2+ offered comple...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi970574p
更新日期：1997-12-09 00:00:00
abstract：:beta-amyloid peptide (Abeta) is the primary constituent of senile plaques, a defining feature of Alzheimer's disease. Aggregated Abeta is toxic to neurons, but the mechanism of toxicity remains unproven. One proposal is that Abeta toxicity results from relatively nonspecific Abeta-membrane interactions. We hypothesize...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0001980
更新日期：2000-08-22 00:00:00
abstract：:The homeodomain proteins a1 and alpha 2 act cooperatively to regulate cell type specific genes in yeast. The basis of the cooperativity is a weak interaction between the two proteins which forms heterodimers that bind DNA tightly and specifically. In this paper, we examine the mechanism of heterodimerization. We show ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00197a033
更新日期：1994-08-09 00:00:00
abstract：:Two site-directed mutant enzymes of the class A beta-lactamase from Staphylococcus aureus PC1 were produced with the goal of blocking the site that in the native enzyme is occupied by the proposed hydrolytic water molecule. The crystal structures of these two mutant enzymes, N170Q and N170M, have been determined and r...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi962242a
更新日期：1996-12-24 00:00:00
abstract：:A number of isomeric diacylglycerophosphocholines and diacylglycero sulfates containing O-acyl and/or S-acyl ester bonds were investigated as substrates for porcine pancreatic phospholipase A2 and its zymogen. A comparison is made with the kinetic properties of the enzyme toward the corresponding glycol detergents pre...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00348a023
更新日期：1985-12-31 00:00:00
abstract：:The HIV-1 fusion peptide serves as a useful model system for understanding viral/target cell fusion, at least to the lipid-mixing stage. Previous solid-state NMR studies have shown that the membrane-bound HIV-1 fusion peptide adopts an extended conformation in a lipid mixture close to that of host cells of the virus. ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0348157
更新日期：2003-10-14 00:00:00
abstract：:The electron density map of the 3D crystal of Photosystem II from Thermosynechococcus vulcanus with a 1.9 Å resolution (PDB: 3ARC ) exhibits, in the two monomers in the asymmetric unit cell, an, until now, unidentified and uninterpreted strong difference in electron density centered at a distance of around 1.5 Å from ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi401213m
更新日期：2013-12-31 00:00:00
abstract：:Glycinamide ribonucleotide transformylase, the first of the two formyl group transferases of de novo purine biosynthesis requiring 10-formyltetrahydrofolate, has been purified 1500-fold, nearly to homogeneity, from the murine lymphoma cell line L5178Y. Purification of the enzyme was facilitated by the use of a gelatin...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00327a008
更新日期：1985-03-12 00:00:00
abstract：:At pH 8.9 and 37 degrees C the half-times for tritium exchange with the C-2 protons of the histidines of trypsin are 73 days for His-57, and greater than 1000 days for His-40 and His-91. These half-times are much longer than the half-life of exchange for the C-2 proton of free histidine (2.8 days at pD 8.2), and longe...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00661a010
更新日期：1976-08-10 00:00:00
abstract：:We reported previously that cdc2 kinase decreased the microtubule-stabilizing ability of a major HeLa cell microtubule-associated protein, MAP4, by phosphorylation in vitro [Ookata, K., et al. (1995) J. Cell Biol. 128, 849-862]. An important question raised by this study is whether MAP4 is indeed phosphorylated by cdc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi971251w
更新日期：1997-12-16 00:00:00
abstract：:We have found a new class of inhibitors of the bacterial bioluminescence reaction, the N,N-diphenylalkylamines and acids. We have studied the action of one of these compounds 2,2-diphenylpropylamine. The amine was competitive with the long-chain aliphatic aldehyde substrate (Ki congruent to 0.1 mM) but caused an incre...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00522a027
更新日期：1981-09-15 00:00:00
abstract：:The sterol (free and esterified cholesterol) transport activity of the small-intestinal brush border membrane was solubilized with the short-chain detergent diheptanoylphosphatidylcholine and reconstituted to an artificial membrane system (proteoliposomes). The resulting proteoliposomes were identified as unilamellar ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi970625i
更新日期：1997-09-02 00:00:00
abstract：:Azotobacter vinelandii bacterioferritin (AvBF) containing 800-1500 Co or Mn atoms as Co(III) and Mn(III) oxyhydroxide cores (Co-AvBF, Mn-AvBF) was synthesized by the same procedure used previously for horse spleen ferritin (HoSF). The kinetics of reduction of Co-AvBF and Mn-AvBF by ascorbic acid are first-order in eac...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi060164d
更新日期：2006-05-09 00:00:00
abstract：:We have measured the temperature dependence of the oxygen-binding isotherms of human and bovine hemoglobin at pH 9.0 in 0.1 M borate buffer. In both hemoglobins the ionization of the Bohr protons is finished at this pH; therefore, their heat does not interfere with the measurements. Two sets of curves have been obtain...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00227a006
更新日期：1991-04-02 00:00:00
abstract：:To characterize the roles played by Glu44 and Glu56 of cytochrome b5 in the formation of the electrostatic complex between cytochrome c and cytochrome b5, the Glu44, Glu56, or both sites were changed to alanine by site-directed mutagenesis. The influence of these two residues on the protein stability was probed by inv...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9805036
更新日期：1998-10-06 00:00:00
abstract：:The ATP binding cassette (ABC) transporters ABCG2 and ABCB1 perform ATP hydrolysis-dependent efflux of structurally highly diverse compounds, collectively called allocrites. Whereas much is known about allocrite-ABCB1 interactions, the chemical nature and strength of ABCG2-allocrite interactions have not yet been asse...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.5b00649
更新日期：2015-10-13 00:00:00
abstract：:The group-specific antigen was isolated from a type Ia group B streptococcal strain and is a complex polysaccharide composed of alpha-L-rhamnopyranosyl, alpha-D-galactopyranosyl, 2-acetamido-2-deoxy-beta-D-glucopyranosyl, D-glucitol, and phosphate residues. The complexity of the group B polysaccharide antigen is evide...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00376a020
更新日期：1987-01-27 00:00:00
abstract：:The properties of the Fe and Mo sites of the iron-molybdenum cofactor of nitrogenase with respect to binding and activation of N(2) have been studied by molecular mechanics calculations on the local protein environment and by density functional theory (DFT) calculations on subsections of the cofactor. The DFT calculat...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi025623z
更新日期：2002-11-26 00:00:00
abstract：:Nitric oxide (NO) synthases (NOS) are thiolate-ligated heme-, tetrahydrobiopterin (BH(4))-, and flavin-containing monooxygenases which catalyze the NADPH-dependent conversion of L-arginine (L-Arg) to NO AND citrulline. NOS consists of two domains: an N-terminal oxygenase (heme- and BH(4)-bound) domain and a C-terminal...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi991580j
更新日期：1999-11-30 00:00:00
abstract：:Lactoferrin (Lf) and serum transferrin (Tf) combine high-affinity iron binding with an ability to release this iron at reduced pH. Lf, however, retains iron to significantly lower pH than Tf, giving the two proteins distinct functional roles. In this paper, we compared the iron-release profiles for human Lf, Tf, and t...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0001224
更新日期：2000-06-06 00:00:00
abstract：:We have used site-directed mutagenesis to alter the [Fe-S] cluster composition of Escherichia coli dimethyl sulfoxide (DMSO) reductase (DmsABC). The electron-transfer subunit (DmsB) of this enzyme contains 16 Cys residues arranged in 4 groups (I-IV) which provide ligands to 4 [4Fe-4S] clusters [Cammack, R., & Weiner, ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00098a003
更新日期：1991-08-27 00:00:00
abstract：:FeNO vibrational frequencies were investigated for a series of myoglobin mutants using isotope-edited resonance Raman spectra of (15/14)NO adducts, which reveal the FeNO and NO stretching modes. The latter give rise to doublet bands, as a result of Fermi resonances with coincident porphyrin vibrations; these doublets ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi026395b
更新日期：2003-05-06 00:00:00
abstract：:As part of our studies on the molecular mechanism of mutation [Chambers, R. W. (1982) in Molecular and Cellular Mechanisms of Mutagenesis (Lemontt, J. F., & Generoso, W. M., Eds.) pp 121-145, Plenum, New York and London], we wanted to prepare specific oligonucleotides carrying O2- or O4-alkylthymidine residues. Since ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00430a007
更新日期：1989-02-21 00:00:00
abstract：:In aqueous glycerol solutions, the rate constant for the formation of compound I of horseradish peroxidase from hydrogen peroxide is independent of the viscosity. However, whem m-chloroperbenzoic acid is used to form compound I, the rate is viscosity dependent, indicating that this reaction is diffusion controlled. Th...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00632a023
更新日期：1977-06-28 00:00:00
abstract：:The helical regions of RNA are generally very stable, but the single-stranded and loop regions often exist as an ensemble of conformations in solution. The theophylline-binding RNA aptamer forms a very stable structure when bound to the bronchodilator theophylline, but the theophylline binding site is not stably forme...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi027103+
更新日期：2003-03-11 00:00:00
abstract：:The ability of avian-specific linker histone H5, and the globular domains of H5 (GH5) and H1(0) (GH1(0), to self-associate either free in solution or when bound to DNA was investigated. All three proteins underwent a salt-dependent increase in turbidity that may be indicative of nonspecific interactions. Dithiobis(suc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi980716v
更新日期：1998-09-08 00:00:00
