Abstract:
:A reinvestigation of the metal ion activation and specificity of CTP synthetase was begun in order to separate effects due to binding of free metal ions and binding of nucleotide-complexed ions. Apo-CTP synthetase was prepared by dialysis against 5 mM EDTA. Analysis of apo-enzyme by atomic absorption spectroscopy revealed that all bound metal ions could be removed. Thus, apo-enzyme contained no detectable amounts of Mg2+, Mn2+, Cu2+, Zn2+, Co2+, Ni2+, or Fe2+. The half-saturation value of Mg(2+)-dependent enzyme activation was approximately 2.6 mM at a total concentration of 2 mM nucleotides (ATP plus UTP). These data suggest that the enzyme requires more Mg2+ for full catalytic activity than required simply to complex the nucleotide substrates. Analysis of velocity versus [Mg2+]free demonstrated that activity depends on [Mg2+]free. The half-saturation values for [Mg2+]free were 660 and 280 microM in the NH4(+)- and glutamine-dependent assays, respectively. The half-saturation values for [Mn2+]free and [Co2+]free were approximately 2.6 and 3.8 microM in the NH4(+)-dependent assay and 2.8 and 4.7 microM in the glutamine-dependent assay. These results are consistent with the presence of a separate binding site for free metal ion on the enzyme. Over the range of 0.1-10 mM, neither Cu2+, Zn2+, Ni2+, nor Ca2+ activated the enzyme. Also, both Cu2+ and Zn2+ were effective inhibitors of CTP synthetase in the absence of dithiothreitol at concentrations < 50 microM. Inhibition by Zn2+ was reversed by EDTA, whereas inhibition by Cu2+ was not. In the presence of dithiothreitol, Zn2+, Co2+ and Ni2+ inhibited the enzyme at less than 200 microM metal ion.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Robertson JG,Villafranca JJdoi
10.1021/bi00065a032subject
Has Abstractpub_date
1993-04-13 00:00:00pages
3769-77issue
14eissn
0006-2960issn
1520-4995journal_volume
32pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::A 31 amino acid fragment of the extracellular N-terminus of the human G-protein coupled receptor for parathyroid hormone (PTH1R) has been structurally characterized by NMR and molecular dynamics simulations. The fragment PTH1R[168-198] includes residues 173-189, shown by photoaffinity cross-linking to be a contact dom...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981265h
更新日期:1998-09-15 00:00:00
abstract::NADH oxidase activity has been detected in luminal membrane derived from the proximal tubules of rat kidney (brush border membranes). The cytochromes associated with these membranes [García, M.L., Benavides, J., Valdivieso, F., Mayor, F., & Giménez-Gallego, G. (1978) Biochem. Biophys. Res. Commun. 82, 738-744] were re...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00562a019
更新日期:1980-10-14 00:00:00
abstract::Escherichia coli 16S RNA from 30S ribosomal subunits was isolated, oxidized at the 3' end, and labeled with the thiosemicarbazide derivatives of fluorescein or eosin. Labeled 16S RNA was reconstituted into 30S subunits. They were almost fully active compared to 30S subunits reconstituted from unlabeled 16S RNA by usin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00521a033
更新日期:1981-09-01 00:00:00
abstract::The first structure of a glycerol kinase from a Gram-positive organism, Enterococcus casseliflavus, has been determined to 2.8 A resolution in the presence of glycerol and to 2.5 A resolution in the absence of substrate. The substrate-induced closure of 7 degrees is significantly smaller than that reported for hexokin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034258o
更新日期:2004-01-20 00:00:00
abstract::Steady-state kinetic parameters were determined for the human leukocyte elastase catalyzed hydrolysis of a series of peptide-based thiobenzyl esters and p-nitroanilides. The peptide units are MeOSuc-Val, MeOSuc-Alan-Pro-Val (n = 0-2), and MeOSuc-Alan-Pro-Ala (n = 1 or 2). The results of this study suggest five importa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00379a015
更新日期:1987-03-10 00:00:00
abstract::The interaction of serine protease (esterases) with 6-chloro-2-pyrones was investigated. Time-dependent inactivation of chymotrypsin, alpha-lytic protease, pig liver elastase, and cholinesterase was found with 3- and 5-benzyl-6-chloro-2-pyrone, as well as 3- and 5-methyl-6-chloro-2-pyrone. No inactivation was observed...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00282a034
更新日期:1983-06-21 00:00:00
abstract::Locusta migratoria apolipophorin III (apoLp-III) is a helix bundle exchangeable apolipoprotein that reversibly binds to lipoprotein surfaces. Structural reorganization of its five amphipathic alpha-helices enables the transition from the lipid-free to lipid-bound state. ApoLp-III-induced transformation of dimyristoylp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010410f
更新日期:2001-06-26 00:00:00
abstract::The tau microtubule-associated proteins are axonal proteins that have been implicated in axonal outgrowth, microtubule spacing, and microtubule bundling. Moreover, tau is the major structural component of the paired helical filaments present in the brains of Alzheimer's disease patients. The Caenorhabditis elegans Gen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi952646n
更新日期:1996-07-23 00:00:00
abstract::A cell-free system for synthesizing protein from wheat germ was used to translate the messenger RNA extracted from 16-day embryonic chick calvaria. A part of the product had properties similar to collagenous peptides and served as a substrate for prolyl hydroxylase, an enzyme specific for collagen. The level of potass...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00649a016
更新日期:1976-02-24 00:00:00
abstract::Decorin-binding protein A (DBPA) is an important lipoprotein from the bacterium Borrelia burgdorferi, the causative agent of Lyme disease. The absence of DBPA drastically reduces the pathogenic potential of the bacterium, and biochemical evidence indicates DBPA's interactions with the glycosaminoglycan (GAG) portion o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi3007093
更新日期:2012-10-23 00:00:00
abstract::The egg jelly that encapsulates amphibian eggs is essential for fertilization, but its molecular composition and roles remain largely unknown. We identified a calcium-dependent lectin from the pentraxin superfamily in the egg jelly coat from the South American burrowing frog, Lepidobatrachus laevis. This lectin, jeltr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035314o
更新日期:2003-11-11 00:00:00
abstract::The solution structure of the 63-residue heregulin-alpha (HRG-alpha) epidermal growth factor (EGF)-like domain, corresponding to residues 177-239 of HRG-alpha, has been determined to high resolution using data from two-dimensional and three-dimensional homo- and heteronuclear NMR spectroscopy. The structure is based o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi952626l
更新日期:1996-03-19 00:00:00
abstract::The translation of a small number of mRNAs in mouse SC-1 fibroblasts can be stimulated by cycloheximide, under conditions where the synthesis of most proteins is inhibited. These mRNAs are ordinarily present in small polyribosomes or messenger ribonucleoprotein particles, although the addition of cycloheximide drives ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00356a030
更新日期:1986-04-22 00:00:00
abstract::The concept of using a dynamic base-pairing nucleobase as a mode for degenerate recognition presents a unique challenge to analysis of DNA structure. Proton and phosphorus NMR studies are reported for two nine-residue DNA oligodeoxyribonucleotides, d(CATGGGTAC).d(GTACNCATG) (1) and d(CATGTGTAC).(GTACNCATG) (2), which ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001448f
更新日期:2001-02-13 00:00:00
abstract::Rh(phen)2phi3+ (phen = 1,10-phenanthroline; phi = 9,10-phenanthrenequinone diimine) avidly binds to DNA via intercalation from the major groove and upon photoactivation produces strand scission with single base 5' asymmetry. Enantiomers of Rh(phen)2phi3+, which lack hydrogen-bonding substituents in ancillary positions...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00180a005
更新日期:1994-04-12 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 C2A domain of synaptotagmin 7 (Syt7) is a Ca(2+) and membrane binding module that docks and inserts into cellular membranes in response to elevated intracellular Ca(2+) concentrations. Like other C2 domains, Syt7 C2A binds Ca(2+) and membranes primarily through three loop regions; however, it docks at Ca(2+) conce...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00422
更新日期:2015-09-22 00:00:00
abstract::The binding of UDP-N-acetylglucosamine (UDPNAG) to the enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) was studied in the absence and presence of the antibiotic fosfomycin by isothermal titration calorimetry. Fosfomycin binds covalently to MurA in the presence of UDPNAG and also in its absence as demonst...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0107041
更新日期:2001-08-21 00:00:00
abstract::We report differences in the interaction of two structurally similar phenanthroline intercalators, ethidium and propidium, with poly(dA).poly(dT) and poly[d(A-T)] as a function of ionic strength based on titration microcalorimetry, fluorescence titration, and hydrostatic pressure measurements. Both ethidium and propid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00472a009
更新日期:1990-05-22 00:00:00
abstract::The apolipoproteins of insect lipophorin were dissociated in guanidinium chloride and isolated by gel permeation chromatography. Over 98% of the total lipid in lipophorin was associated with apolipophorin I (apoLp-I), thus suggesting this apolipoprotein to be the lipid binding component of the particle. ApoLp-I was de...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00442a019
更新日期:1989-08-08 00:00:00
abstract::The nuclear tRNA 3' processing activity from wheat has been characterized and partially purified. Several characteristics of the wheat nuclear 3' processing enzyme now allow this activity to be distinguished from its mitochondrial counterpart. The nuclear enzyme is an endonuclease, which we termed nuclear RNase Z. The...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992253e
更新日期:2000-02-29 00:00:00
abstract::Using our Escherichia coli expression system, we have produced five mutant recombinant (r) hemoglobins (Hbs): r Hb (alpha V96 W), r Hb Presbyterian (beta N108K), r Hb Yoshizuka (beta N108D), r Hb (alpha V96W, beta N108K), and r Hb (alpha V96W, beta N108D). These r Hbs allow us to investigate the effect on the structur...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990286o
更新日期:1999-07-06 00:00:00
abstract::We obtained a novel carbohydrate-binding peptide having a helix-loop-helix scaffold from a random peptide library. The helix-loop-helix peptide library randomized at five amino acid residues was displayed on the major coat protein of a filamentous phage. Affinity selection with a ganglioside, Galbeta1-3GalNAcbeta1-4(N...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi8000837
更新日期:2008-07-01 00:00:00
abstract::The fidelity of DNA strand transfer reactions catalyzed by human immunodeficiency virus type 1 reverse transcriptase has been studied in vitro. A model system involving two sequential DNA strand transfers was developed to simulate the process of forced copy-choice recombination. A propensity for nucleotide misincorpor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00179a014
更新日期:1994-04-05 00:00:00
abstract::4-Oxalocrotonate tautomerase (EC 5.3.2-; 4-OT), a hexamer consisting of 62 residues per subunit, catalyzes the isomerization of unsaturated alpha-keto acids, converting unconjugated ketones to the conjugated isomers via a dienolic intermediate. The recently solved crystal structure of an isozyme of 4-OT suggests that ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi951077g
更新日期:1996-01-23 00:00:00
abstract::Nucleolin, also called protein C23, is a RNA-associated protein implicated in the early stages of ribosome assembly. To study the general conformation and map the nucleic acid binding regions, rat nucleolin was subjected to limited proteolysis using trypsin and chymotrypsin in the presence or absence of poly(G). The c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00476a006
更新日期:1990-06-19 00:00:00
abstract::In order to elucidate the molecular mechanisms responsible for the apparent nonlinear behavior of the temperature dependence of the redox potential of Hydrogenobacter thermophilus cytochrome c552 [Takahashi, Y., Sasaki, H., Takayama, S. J., Mikami, S., Kawano, S., Mita, H., Sambongi, Y., and Yamamoto, Y. (2006) Bioche...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7000714
更新日期:2007-08-14 00:00:00
abstract::4-Azido-2-nitrophenyl pyrophosphate (azido-PPi) labeled with 32P in the alpha position was prepared and used to photolabel beef heart mitochondrial F1. Azido-PPi was hydrolyzed by yeast inorganic pyrophosphatase, but not by mitochondrial F1-ATPase. Incubation of F1 with [alpha-32P]azido-PPi in the dark under condition...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00452a021
更新日期:1989-12-26 00:00:00
abstract::Purified subunits of intermediate filaments obtained from a variety of tissues and cell types contain O-phosphoserine and, in some cases, smaller amounts of O-phosphothreonine. The O-phosphoserine content was estimated by reaction of performic acid oxidized subunits with methylamine in NaOH. Decamin of BHK-21 and CHO ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00530a030
更新日期:1982-01-05 00:00:00
abstract::Several peptides contained within the C-terminal sequence of the B2 subunit of Escherichia coli ribonucleotide reductase (RNR) were investigated for their ability to inhibit the enzyme, presumably by interfering with association of the B1 and B2 subunits. AcYLVGQIDSE, corresponding by sequence homology to a nonapeptid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00247a008
更新日期:1991-08-20 00:00:00