Abstract:
:Cytidine deaminase from Escherichia coli contains 1 mol of tightly bound zinc per enzyme subunit (Yang, C., Carlow, D., Wolfenden, R., & Short, S.A. (1992) Biochemistry 31, 4168-4174). When the metal liganding residues Cys-129 and Cys-132 were replaced by Ala, and His-102 was replaced by Ala, Asn, or Gln, deaminase activities of cell extracts containing these mutant enzymes were decreased by several orders of magnitude relative to that of the wild-type enzyme. After purification, each mutant protein was found to contain less than 0.2 mol of zinc per enzyme subunit, except mutant H102Q, which contained 1 mol of zinc per subunit. The activity of each mutant enzyme increased in the presence of added zinc but never attained wild-type activity. Mutant H102N was unique in that this protein could be purified as a stable apoenzyme, activated by added zinc, and then inhibited by EDTA. This mutant enzyme bound zinc with an apparent Kd value of 6.0 x 10(-10) M and regained maximal activity in the presence of 1 mol of zinc per subunit. Affinities of the mutant cytidine deaminases for the transition-state analogue, 5-fluoropyrimidin-2-one ribonucleoside (3,4) hydrate, were found to decrease in rough proportion to kcat/Km over a range spanning several orders of magnitude. This variation in catalytic efficiency arose mainly from effects on kcat, indicating the involvement of zinc coordination in the catalytic process rather than in substrate binding.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Smith AA,Carlow DC,Wolfenden R,Short SAdoi
10.1021/bi00187a012subject
Has Abstractpub_date
1994-05-31 00:00:00pages
6468-74issue
21eissn
0006-2960issn
1520-4995journal_volume
33pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Tryptic digestion studies of the human erythrocyte glucose carrier have shown that a reactive and transport-sensitive exofacial sulfhydryl is located in the carboxy-terminal half of the molecule, corresponding to Cys347, Cys421, or Cys429. In the present studies, the erythrocyte glucose carrier labeled on the exofacia...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00497a014
更新日期:1990-11-13 00:00:00
abstract::Calcineurin, a Ca2+, calmodulin-dependent protein phosphatase, was recently found to bind with high affinity to two different immunosuppressant binding proteins (immunophilins) with absolute dependence on the presence of the immunosuppressants FK506 or cyclosporin A (CsA) [Liu et al. (1991) Cell 66, 807-815]. The bind...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00131a002
更新日期:1992-04-28 00:00:00
abstract::The lipid fatty acid composition of the cytoplasmic membranes of Escherichia coli can be varied by growing an unsaturated fatty acid auxotroph in the presence of different fatty acid supplements. Electron spin resonance (ESR) studies of spin-label partitioning into the cytoplasmic membranes of different lipid fatty ac...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00627a015
更新日期:1977-04-19 00:00:00
abstract::Activation of washed human platelets initiated with alpha-thrombin, SFLLRN, or AYPGKF invariably results in the generation of PAR-1-(1-41) and PAR-4-(1-47). PAR-1-(1-41) and PAR-4-(1-47) are amino-terminal peptides generated when PAR-1 and -4 are cleaved in their first extracellular domains after R(41) and R(47), resp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801399c
更新日期:2009-02-24 00:00:00
abstract::By superimposing data obtained by photo-cross-linking RGD-containing ligands to the human alpha(V)beta(3) integrin onto the crystal structure of the ectopic domain of this receptor (Xiong et al. (2001) Science 294, 339-345), we have identified the binding site for the RGD triad within this integrin. We synthesized thr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025690t
更新日期:2002-07-02 00:00:00
abstract::Vaccinia DNA topoisomerase, a 314 amino acid type I enzyme, catalyzes the cleavage and rejoining of DNA strands through a DNA-(3'-phosphotyrosyl)-enzyme intermediate formed at a specific target sequence, 5'-(C/T)CCTT downward arrow. To identify amino acids that participate in the DNA binding and transesterification st...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970498q
更新日期:1997-07-01 00:00:00
abstract::The structural factors responsible for the extraordinary rate enhancement ( approximately 10(17)) of the reaction catalyzed by orotidine 5'-monophosphate decarboxylase (OMPDC) have not been defined. Catalysis requires a conformational change that closes an active site loop and "clamps" the orotate base proximal to hyd...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100443a
更新日期:2010-05-04 00:00:00
abstract::DNA-dependent synthesis of beta-galactosidase was optimized in extracts made from cells lysed by a standard French pressure cell. Extracts made at 3200 psi synthesized up to 25-fold more beta-galactosidase than extracts made at 7500 psi. beta-Galactosidase synthesis was cyclic 3', 5' AMP dependent, as expected, and in...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a016
更新日期:1977-03-08 00:00:00
abstract::Hemophores from Serratia marcescens (HasA(sm)) and Pseudomonas aeruginosa (HasA(p)) bind hemin between two loops, which harbor the axial ligands H32 and Y75. Hemin binding to the Y75 loop triggers closing of the H32 loop and enables binding of H32. Because Yersinia pestis HasA (HasA(yp)) presents a Gln at position 32,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400280z
更新日期:2013-04-23 00:00:00
abstract::The inflammatory mediator nitric oxide (NO*) promotes apoptotic cell death based on morphological evidence, accumulation of the tumor suppressor p53, caspase-3 activation, and DNA fragmentation in RAW 264.7 macrophages. Since nitrosothiols may actually be the predominant form of biologically active NO* in vivo, we use...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982292a
更新日期:1999-02-23 00:00:00
abstract::Sensory rhodopsin II (SRII) is unique among the archaeal rhodopsins in having an absorption maximum near 500 nm, blue shifted roughly 70 nm from the other pigments. In addition, SRII displays vibronic structure in the lambda(max) absorption band, whereas the other pigments display fully broadened band maxima. The mole...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0116487
更新日期:2001-11-20 00:00:00
abstract::The Escherichia coli ribosomal protein S4 is known to repress translation of its own gene and several other ribosomal protein (r-protein) genes in the alpha operon as part of a general mechanism coordinating the levels of rRNA and r-protein synthesis. Using a filter binding assay and RNA transcripts prepared in vitro,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00348a002
更新日期:1985-12-31 00:00:00
abstract::The heterotrimeric G protein subunit, alpha(s), can move reversibly from plasma membranes to cytoplasm in response to activation by GPCRs or activating mutations. We examined the importance of the unique N-terminus of alpha(s) in this translocation in cultured cells. alpha(s) contains a single site for palmitoylation ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025533u
更新日期:2002-07-30 00:00:00
abstract::Double-stranded complementary deoxyribonucleic acid (cDNA) transcribed in vitro from a partially pure myosin light-chain messenger ribonucleic acid (mRNA) of the chick embryonic heart was cloned in Escherichia coli strain chi 1776 by using the HindIII cleavage site in the plasmid pBR322. The insertion of essentially f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00592a019
更新日期:1979-12-11 00:00:00
abstract::Exposure of mammalian cells (transformed mouse fibroblasts or rat hepatoma cells) to S-adenosyl-1,8-diamino-3-thiooctane produced profound changes in the intracellular polyamine content. Putrescine was increased and spermidine was decreased, consistent with the inhibition of spermidine synthase by this compound, which...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00263a036
更新日期:1982-09-28 00:00:00
abstract::The vibrations of a water molecule in the water-oxidizing complex (WOC) of photosystem II were detected for the first time using Fourier transform infrared (FTIR) spectroscopy. In a flash-induced FTIR difference spectrum upon the S(1)-to-S(2) transition, a pair of positive and negative bands was observed at 3618 and 3...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001040i
更新日期:2000-09-12 00:00:00
abstract::Excitation energy transfer studies were carried out to determine the distance between the adenosinetriphosphatase (ATPase) site and a unique "fast-reacting" sulfhydryl (referred to as SH1) in myosin subfragment 1. The fluorescent moiety of the probe N-(iodoacetyl)-N'-(5-sulfo-1-naphthyl)ethylene-diamine was used as th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00520a035
更新日期:1981-08-18 00:00:00
abstract::The stability and folding kinetics of wild-type and a mutant staphylococcal nuclease (SNase) at neutral pH are significantly perturbed by the presence of moderate to high concentrations of salts. Very substantial increases in stability toward thermal and urea denaturation were observed; for example, 0.4 M sodium sulfa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi000861k
更新日期:2001-02-20 00:00:00
abstract::We have performed a kinetic and thermodynamic analysis of 3D(pol) derivatives containing substitutions in the ribose-binding pocket with ATP analogues containing correct and incorrect sugar configurations. We find that Asp-238, a residue in structural motif A that is conserved in all RNA-dependent RNA polymerases, is ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035429s
更新日期:2004-05-11 00:00:00
abstract::We report the first experimental characterization of the full thermodynamic profile for binding of urea to a native protein. We measured the volumetric parameters of lysozyme at pH 7.0 as a function of urea within a temperature range of 18-45 °C. At neutral pH, lysozyme retains its native conformation between 0 and 8 ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00805
更新日期:2016-11-29 00:00:00
abstract::The addition of a small peptide can significantly increase the rate at which pepsin cleaves a substrate at pH 4.5. Why? In order to find out, we have determined spectrophotometrically the relative ability of over a dozen peptides to speed the initial rate of disappearance of Phe-Trp-NH2 and Leu-Trp-Met-Arg. Here are s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00514a029
更新日期:1981-05-26 00:00:00
abstract::Drug intervention that prevents reabsorption of circulating bile acids by the apical (ileal) sodium/bile acid cotransporter (ASBT) may be a promising new therapy for lowering of plasma cholesterol. 2164U90 is a benzothiazepine-based competitive inhibitor of bile acid transport with K(i) values of approximately 10 and ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0205404
更新日期:2002-12-17 00:00:00
abstract::Cytochrome P450BM-3 is a fatty acid monooxygenase that contains the catalytic P450 heme domain covalently attached to a diflavin P450 reductase domain. The function of the linker region connecting the C-terminal end of the heme domain to the N-terminal end of the reductase domain has been studied by deleting parts of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00035a031
更新日期:1995-09-05 00:00:00
abstract::A novel phosphotriesterase was recently discovered and purified from Sphingobium sp. TCM1 (Sb-PTE) and shown to catalyze the hydrolysis of a broad spectrum of organophosphate esters with a catalytic efficiency that exceeds 10(6) M(-1) s(-1) for the hydrolysis of triphenyl phosphate. The enzyme was crystallized and the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00364
更新日期:2016-07-19 00:00:00
abstract::The side chain of the antifungal polyketide ansatrienin A produced by Streptomyces collinus contains a cyclohexanecarboxylic acid (CHC) derived moiety. This CHC in the coenzyme A activated form (CHC-CoA) is derived from shikimic acid via a pathway in which the penultimate step is the isomerization of 2-cyclohexenylcar...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0005714
更新日期:2000-06-27 00:00:00
abstract::Fully functional variable fragments (Fv) of D1.3, a mouse antibody directed against the hen egg lysozyme, were readily produced as hybrids (Fv-MalE) with the maltose-binding protein of Escherichia coli and purified independently of their antigen-binding properties. We used site-directed mutations of residues in the co...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961419y
更新日期:1997-01-07 00:00:00
abstract::MAP kinase kinase (MAPKK) is a dual specificity protein kinase that phosphorylates and activates MAP kinase in vivo. In this study, four mouse monoclonal single-chain Fv (scFv) antibodies (Y1-6, Y1-7, Y3-6, and Y3-11) that can specifically bind to Xenopus MAPKK were isolated from combinatorial scFv-displaying phage li...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi960956f
更新日期:1996-10-08 00:00:00
abstract::The dependence of calcineurin on Ca2+ for activity is the result of the concerted action of calmodulin, which increases the turnover rate of the enzyme and modulates its response to Ca2+ transients, and of calcineurin B, which decreases the Km of the enzyme for its substrate. The calmodulin-stimulated protein phosphat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00188a015
更新日期:1994-06-07 00:00:00
abstract::The gel to liquid-crystalline phase transition temperatures of dispersions of mixed-acid sn-1,2-lecithins which contain one unsaturated and one saturated fatty acid have been studied by differential scanning calorimetry. The temperature for 1-oleoyl-2-palmitoyl-sn-glycero-3-phosphocholine (containing no reversed isome...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00515a051
更新日期:1981-06-09 00:00:00
abstract::Tyramine β-monooxygenase (TβM), the insect homologue of dopamine β-monooxygenase, is a neuroregulatory enzyme that catalyzes the β-hydroxylation of tyramine to yield octopamine. Mutation of the methionine (Met) ligand to Cu(M) of TβM, Met471Cys, yielded a form of TβM that is catalytically active but susceptible to ina...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300456f
更新日期:2012-09-25 00:00:00