Abstract:
:Aspartate transcarbamoylase from Escherichia coli is a dodecameric enzyme consisting of two trimeric catalytic subunits and three dimeric regulatory subunits. The X-ray structure of this enzyme indicates that the side chains of His-41, Asp-100, and Asp-90 from one catalytic chain form interactions with the side chains of Glu-37, Arg-65, and Arg-269, respectively, from an adjacent catalytic chain. In order to determine whether these interactions are important for the structural stabilization of the enzyme and/or homotropic and heterotropic effects, four mutant versions of aspartate transcarbamoylase, Glu-37-->Ala, Asp-100-->Asn, Asp-100-->Ala, and Arg-269-->Ala, were created by site-specific mutagenesis. The Glu-37-->Ala holoenzyme exhibits essentially wild-type behavior with respect to homotropic cooperativity and heterotropic regulation by ATP and CTP. The Glu-37-->Ala catalytic subunit exhibits a half-life of inactivation at 69 +/- 0.5 degrees C of 4.9 min, as compared to 5.8 min for the wild-type catalytic subunit. The Asp-100-->Asn and Asp-100-->Ala holoenzymes are slightly more active than the wild-type holoenzyme, exhibit 1.4-fold and 1.8-fold reductions in the aspartate concentration at half the maximal specific activity, respectively, and show increased affinities for ATP and CTP. Both the Asp-100-->Asn and Asp-100--> Ala catalytic subunits exhibit a 2-fold reduction in the half-life of inactivation at 69 +/- 0.5 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Baker DP,Kantrowitz ERdoi
10.1021/bi00089a034subject
Has Abstractpub_date
1993-09-28 00:00:00pages
10150-8issue
38eissn
0006-2960issn
1520-4995journal_volume
32pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The bifunctional enzyme dehydroquinate dehydratase-shikimate dehydrogenase (DHQ-SDH) catalyzes the dehydration of dehydroquinate to dehydroshikimate and the reduction of dehydroshikimate to shikimate in the shikimate pathway. We report the first crystal structure of Arabidopsis DHQ-SDH with shikimate bound at the SDH ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060366+
更新日期:2006-06-27 00:00:00
abstract::The equilibrium between the rat brain tubulin alpha beta dimer and the dissociated alpha and beta monomers has been studied by analytical ultracentrifugation with use of a new method employing short solution columns, allowing rapid equilibration and hence short runs, minimizing tubulin decay. Simultaneous analysis of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00228a023
更新日期:1991-04-09 00:00:00
abstract::Ca2+-activated Z-disk-removing activity in the P0-40 crude muscle extracts described by Busch et al. (Busch, W. A., Stromer, M. H., Goll, D. E., and Suzuki, A. (1972), J. Cell Biol. 52, 367) was purified from porcine skeletal muscle extracts by using five column chromatographic procedures in succession: (1) 6% agarose...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00655a019
更新日期:1976-05-18 00:00:00
abstract::This paper presents the crystal structure of porcine pancreatic carboxypeptidase B (pp-CpB) in complex with a variety of thiol-based inhibitors that were developed as antagonists of activated thrombin-activatable fibrinolysis inhibitor (TAFIa). Recent studies have indicated that a selective inhibitor of TAFIa could en...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0501941
更新日期:2005-07-05 00:00:00
abstract::In Escherichia coli, the cyclic AMP receptor protein (CRP) serves as a sensor of the intracellular level of cyclic AMP. At increasing concentrations of cyclic AMP, CRP becomes activated upon binding a cyclic AMP molecule. The activated CRP is capable of regulating the expression of more than 20 genes by binding to spe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972450i
更新日期:1998-04-14 00:00:00
abstract::The effects of ionophore A23187 on the movements of Ca2+, Mg2+, H+ phosphate, and succinate and its effects on energy utilization by mitochondria have been studied as a function of ionophore concentrations. At a low ratio of the compound to mitochondrial protein, below that required for maximal uncoupling, an apparent...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00657a032
更新日期:1976-06-15 00:00:00
abstract::Papain-solubilized human class II (HLA-DR) antigens have been purified from cadaveric spleens by ion-exchange chromatography, gel chromatography, and immunosorbent purification. The isolated papain-solubilized antigens comprised two subunits with apparent molecular weights of 23 000 and 30 000, respectively. The circu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00264a036
更新日期:1982-10-12 00:00:00
abstract::Thermodynamic parameters of helix formation were measured spectroscopically for 16 oligoribonucleotides containing either internal GU mismatches or the corresponding AU pairs. Internal GU mismatches stabilize each helix, but not as much as the corresponding AU pairs. The differences in the enthalpy and entropy changes...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00367a061
更新日期:1986-09-23 00:00:00
abstract::Structures of several voltage-gated sodium (NaV) channels from bacteria have been determined recently, but the same feat might not be achieved for the mammalian counterparts in the near future. Thus, at present, computational studies of the mammalian NaV channels have to be performed using homology models based on the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01324
更新日期:2016-03-29 00:00:00
abstract::Probing and interrogating protein interactions that involve acyl carrier proteins (ACP's) in fatty acid synthases and polyketide synthases are critical to understanding the molecular basis for the programmed assembly of complex natural products. Here, we have used unnatural amino acid mutagenesis to site specifically ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500936u
更新日期:2014-12-09 00:00:00
abstract::The influenza virus RNA-dependent RNA polymerase protein complex contains an associated RNA endonuclease activity, which cleaves host mRNA precursors in the cell nucleus at defined positions 9-15 nucleotides downstream of the cap structure. This reaction provides capped oligoribonucleotides, which function as primers ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9828932
更新日期:1999-04-27 00:00:00
abstract::Human S100B(beta beta) is a small intracellular EF-hand calcium-binding protein that consists of two noncovalently associated 91-residue beta monomers. The three-dimensional structures of S100B reveal the dimer interface consists of four alpha-helices (I, I' and IV, IV') packed in an X-type bundle. In this study, guan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0118052
更新日期:2002-03-19 00:00:00
abstract::We introduce here a new model to describe the binding of extrinsic membrane proteins to acidic lipid membranes. In this view, macroscopic binding affinity is determined by two processes: nonspecific adsorption of protein to the membrane surface and association of acidic lipids with specific sites on the bound protein....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00444a045
更新日期:1989-09-05 00:00:00
abstract::Histamine is released from mast cells and basophils by either immunological or nonimmunological mechanisms. Histamine, which is the most potent short acting mediator released from these cells, exerts its diverse biological actions by binding to cell surface histamine receptors. We report the affinity purification of h...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00182a008
更新日期:1994-04-26 00:00:00
abstract::Residual dipolar couplings (RDCs) were used as restraints in fully solvated molecular dynamics simulations of reduced substrate- and carbonmonoxy-bound cytochrome P450(cam) (CYP101A1), a 414-residue soluble monomeric heme-containing camphor monooxygenase from the soil bacterium Pseudomonas putida. The (1)D(NH) residua...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101820d
更新日期:2011-03-15 00:00:00
abstract::SHP (short heterodimer partner) is an orphan nuclear receptor, first described for its interaction with nuclear receptors. This study explores a new way of inhibiting the androgen-signaling pathway. We demonstrated that SHP inhibited up to 97% of AR-induced activity. Characterization of AR/SHP interaction provided evi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011384o
更新日期:2001-12-18 00:00:00
abstract::Conformational changes in the prion protein cause transmissible spongiform encephalopathies, also referred to as prion diseases. In its native state, the prion protein is innocuous (PrPC), but it can misfold into a neurotoxic and infectious isoform (PrPSc). The full-length cellular form of the prion protein consists o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0619066
更新日期:2007-03-20 00:00:00
abstract::We studied the urea-induced unfolding transition of staphylococcal nuclease (SNase) and its five proline mutants (P47A, P47T, P117G, P47T/P117G, and P47A/P117G) [corrected] by peptide and aromatic circular dichroism and aromatic absorption spectroscopy at equilibrium and the refolding-unfolding kinetics of the protein...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi963174v
更新日期:1997-05-27 00:00:00
abstract::The high-frequency resonance Raman spectra of FeIII yeast native cytochrome c peroxidase (CCP) and five of its mutants [CCP(MI), Phe-51, Leu-48, Lys-48, Asn-235, and Phe-191] were recorded in phosphate buffer, pH 7.0, and in glycerol/phosphate mixtures at 295 and 10 K. Glycerol induces heme coordination changes in som...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00438a024
更新日期:1989-06-13 00:00:00
abstract::The fusion of different protein domains via peptide linkers is a powerful, modular approach to obtain proteins with new functions. A detailed understanding of the conformational behavior of peptide linkers is important for applications such as fluorescence resonance energy transfer (FRET)-based sensor proteins and mul...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi061288t
更新日期:2006-11-07 00:00:00
abstract::Calpains are intracellular calcium-activated cysteine proteases whose unregulated proteolysis following the loss of calcium homeostasis can lead to acute degeneration during ischemic episodes and trauma, as well as Alzheimer's disease and cataract formation. The determination of the crystal structure of the proteolyti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060425j
更新日期:2006-06-20 00:00:00
abstract::31P NMR spectra of equilibrium mixtures of enzyme-bound reactants and products of the adenylate kinase reaction (formula; see text) were analyzed by using computer simulations based on density matrix theory of chemical exchange. Since adenylate kinase has the unique feature that the reactants in the reverse direction ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00300a025
更新日期:1984-02-28 00:00:00
abstract::Lamin A protein, encoded by the LMNA gene, belongs to the type V intermediate filament protein family and is a major nuclear protein component of higher metazoan organisms, including humans. Lamin A along with B-type lamins impart structural rigidity to the nucleus by forming a lamina that is closely apposed to the in...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400337t
更新日期:2013-06-18 00:00:00
abstract::The initial hydrolysis of CaATP by chloroplast coupling factor 1 was studied with the quenched-flow method. The time course of hydrolysis can be described as a first-order conversion of the enzyme to an active form followed by steady-state formation of product. The rat constant for the first-order process is independe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00382a035
更新日期:1987-04-21 00:00:00
abstract::The binding site of the dopamine D2 receptor, like that of other homologous G protein-coupled receptors, is contained within a water-accessible crevice formed among its seven membrane-spanning segments. Using the substituted-cysteine accessibility method, we previously mapped the residues in the third, fifth, and seve...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972241y
更新日期:1998-01-27 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::An endonuclease II preparation from Escherichia coli makes single strand breaks in DNA which has been treated with the carcinogen 7-bromomethyl-12-methylbenz[alpha]anthracene. In addition, the enzyme preparation excises N6-(12-methylbenz[alpha]anthracenyl-7-methyl)adenine and N2-(12-methylbenz[alpha]anthracenyl-7-met...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00697a002
更新日期:1975-12-30 00:00:00
abstract::Arginine-70 of human dihydrofolate reductase (hDHFR) is a highly conserved residue which X-ray crystallographic data have shown to interact with the alpha-carboxylate of the terminal L-glutamate moiety of either folic acid or methotrexate (MTX). The rationale for this study was to introduce a conservative amino acid r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00247a005
更新日期:1991-08-20 00:00:00
abstract::Oligoribonucleotide binding to baker's yeast initiator tRNA was measured by equilibrium dialysis in order to determine which regions of the tRNA were free to bind complementary oligomers and which were involved in secondary and tertiary structure. Association constants of trinucleoside diphosphates and tetranucleoside...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00686a004
更新日期:1975-07-29 00:00:00
abstract::The major excreted protein (MEP) of transformed mouse fibroblasts has been purified, and monospecific antisera against it have been prepared. Synthesis and secretion of this protein have previously been shown to be stimulated by transformation or treatment with tumor-promoting phorbol esters, but its function is still...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00509a039
更新日期:1981-03-17 00:00:00