Abstract:
:The kcat and Km values for the bovine heart low molecular weight phosphotyrosyl protein phosphatase catalyzed hydrolysis of 16 aryl phosphate monoesters and of five alkyl phosphate monoesters having the structure Ar(CH2)nOPO3H2 (n = 1-5) were measured at pH 5.0 and 37 degrees C. With the exception of alpha-naphthyl phosphate and 2-chlorophenyl phosphate, which are subject to steric effects, the values of kcat are effectively constant for the aryl phosphate monoesters. This is consistent with the catalysis being nucleophilic in nature, with the existence of a common covalent phosphoenzyme intermediate, and with the breakdown of this intermediate being rate-limiting. In contrast, kcat for the alkyl phosphate monoesters is much smaller and the rate-limiting step for these substrates is interpreted to be the phosphorylation of the enzyme. A single linear correlation is observed for a plot of log (kcat/Km) vs leaving group pKa for both classes of substrates at pH 5.0: log (kcat/Km) = -0.28pKa + 6.88 (n = 19, r = 0.89), indicating a uniform catalytic mechanism for the phosphorylation event. The small change in effective charge (-0.28) on the departing oxygen of the substrate is similar to that observed in the specific acid catalyzed hydrolysis of monophosphate monoanions (-0.27) and is consistent with a strong electrophilic interaction of the enzyme with this oxygen atom in the transition state. The D2O solvent isotope effect and proton inventory experiments indicate that only one proton is "in flight" in the transition state of the phosphorylation process and that this proton transfer is responsible for the reduction of effective charge on the leaving oxygen.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Zhang ZY,Van Etten RLdoi
10.1021/bi00101a006subject
Has Abstractpub_date
1991-09-17 00:00:00pages
8954-9issue
37eissn
0006-2960issn
1520-4995journal_volume
30pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Properties of the mycobacterial polymethylpolysaccharide-lipid complex have been investigated by fluorometric techniques. From the dissociation constant for the O-methyglucose polysaccharide-parinaric acid complex at 293 K, a Gibbs free energy (delta G degree) of -33.65 kJ/mol was obtained. The Kd decreased with incre...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00415a064
更新日期:1988-07-26 00:00:00
abstract::Trypsin cleavage has been used to probe structure-function relationships of the Escherichia coli ATP synthase (ECF1F0). Trypsin cleaved all five subunits, alpha, beta, gamma, delta, and epsilon, in isolated ECF1. Cleavage of the alpha subunit involved the removal of the N-terminal 15 residues, the beta subunit was cle...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00402a016
更新日期:1988-01-26 00:00:00
abstract::Histone redistributions between endogenous DNA in calf thymus chromatin and exogenous DNA from Clostridium perfringens (69% A + T) or from Micrococcus luteus (30% A + T) induced by 0.6 M NaCl or by 2% formaldehyde were studied by thermal denaturation. The observed redistribution occurred on histone Hl when the exogeno...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a002
更新日期:1976-10-19 00:00:00
abstract::Two-dimensional (2D) proton magnetic resonance techniques used in conjunction with laser photochemically induced dynamic nuclear polarization (photo-CIDNP) spectroscopy have been applied to studying the kringle 4 domain from human plasminogen at 360 MHz. Out of 11 potential CIDNP-sensitive aromatic side chains, only 5...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00372a020
更新日期:1986-12-02 00:00:00
abstract::The C-terminal src kinase (CSK) is a ubiquitously expressed, cytosolic enzyme capable of phosphorylating and inactivating several plasma membrane-bound src-family protein tyrosine kinases in vitro [Nada, S., Okada, M., MacAuley, A., Cooper, J.A., & Nakagawa, H. (1990) Nature 351, 69-72; Bergman, M., Mustelin, T., Oetk...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9603940
更新日期:1996-09-10 00:00:00
abstract::In the globin family, similarities in the folding mechanism have been found among different mammalian apomyoglobins (apoMb). The best-characterized intermediate of sperm whale apoMb, called I(AGH), is mainly stabilized by nativelike contacts among the A, G, and H helices involving a cluster of hydrophobic residues tha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035319l
更新日期:2004-01-13 00:00:00
abstract::The DNA strand cleavage reaction catalyzed by endonuclease III from Escherichia coli (endo III) on the 3'-side of aldehyde abasic sites proceeds by a syn beta-elimination involving abstraction of the 2'-pro-S proton and formation of a trans alpha,beta-unsaturated aldose product; we previously reported the same stereoc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00218a033
更新日期:1991-01-29 00:00:00
abstract::Analogs of EPSP (4-8) have been prepared, and their activity as substrates for the chorismate synthase from Neurospora crassa has been characterized kinetically. The enzyme appears to show strict discrimination against substitution at the Z-position of the enol ether side chain as well as against substitution at the S...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00251a019
更新日期:1994-11-29 00:00:00
abstract::Among the major obstacles to pharmacological and structural studies of integral membrane proteins (MPs) are their natural scarcity and the difficulty in overproducing them in their native form. MPs can be overexpressed in the non-native state as inclusion bodies, but inducing them to achieve their functional three-dim...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0616706
更新日期:2006-11-28 00:00:00
abstract::A hairpin structure contains two conformationally distinct domains: a double-helical stem with Watson-Crick base pairs and a single-stranded loop that connects the two arms of the stem. By extensive 1D and 2D 500-MHz 1H NMR studies in H2O and D2O, it has been demonstrated that the DNA oligomers d(CGCCGCAGC) and d(CGCC...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00398a027
更新日期:1987-12-01 00:00:00
abstract::The structure of the His-94-->Cys variant of human carbonic anhydrase II (CAII) has been determined by X-ray crystallographic methods to a resolution of 2.3 A with a final crystallographic R factor of 0.155. This variant of CAII crystallizes in orthorhombic space group P2(1)2(1)2(1) which is the first example of a new...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00057a015
更新日期:1993-02-16 00:00:00
abstract::Ultraviolet (uv)-light-mediated formation of protein-DNA adducts in Chinese hamster cell chromatin was investigated in an attempt to compare chromatin alterations induced in vitro with those observed in vivo. Three independent methods of analysis indicated stable protein-DNA associations: (1) a membrane filter assay w...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00653a019
更新日期:1976-04-20 00:00:00
abstract::Many investigations have revealed that ribosome numbers increase in parallel with the growth rate of cells. Here we show that the absolute level of protein synthesis may not be the only factor influencing rRNA synthesis in a nondividing eukaryotic cell. Under conditions of complete (greater than 99%) inhibition of pro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00502a003
更新日期:1990-12-18 00:00:00
abstract::Chemical and enzymatic probing (footprinting) of the reactivity of the promoter DNA backbone is applied to characterize two binary open complexes RPo1 (-Mg2+) and RPo2 (+Mg2+), formed by Escherichia coli RNA polymerase (E sigma 70) at the lambda PR promoter. We report that HO. detects major differences in backbone rea...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00048a004
更新日期:1995-12-05 00:00:00
abstract::When Pseudomonas putida ATCC 39167 and plant-deleterious Pseudomonas fluorescens A225 were grown in an iron-deficient culture medium, they each produced two different novel yellow-green fluorescent pseudobactins: P39167-I, II and PA225-I, II. Pseudobactin P39167-I has a molecular formula of C46H65O23N13 and is monoani...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962670g
更新日期:1997-04-08 00:00:00
abstract::The pH dependence of buffer catalysis of exchange of the C-4 amino protons of cyclic cytosine 2',3'-monophosphate (cCMP) and the N-1 proton of cyclic guanosine 2',3'-monophosphate (cGMP) conforms to an exchange mechanism, in which protonation of the nucleobases at C(N-3) AND G(N-7) establishes the important intermedia...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00608a035
更新日期:1978-07-25 00:00:00
abstract::The structural and functional roles of two conserved active site residues, Arg-97 and Arg-132, in chicken muscle adenylate kinase (AK) were evaluated by site-directed mutagenesis in conjunction with one- and two-dimensional proton nuclear magnetic resonance (NMR), kinetics, and guanidine hydrochloride-induced denatura...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00142a022
更新日期:1992-07-14 00:00:00
abstract::The binding of the codon UUC to the isolated anticodon loop of tRNAPhe (yeast) has been studied as a model of codon recognition by a simple adaptor. Fluorescence titrations demonstrate that UUC binds to the isolated anticodon loop with an equilibrium constant of 1.4 X 10(3) M-1 (at 7.2 degrees C). Equilibrium sediment...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00369a005
更新日期:1986-10-21 00:00:00
abstract::Prokaryotic promoters have been extensively studied to relate sequence features to promoter function. Here we examine the relationship between double-helix stability and promoter activity. The double-helix stability is evaluated from sequence data by free energy computation, based on reported values of dinucleotide fr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00414a035
更新日期:1988-07-12 00:00:00
abstract::The sucrose permease (CscB) and lactose permease (LacY) of Escherichia coli belong to the oligosaccharide/H(+) symporter subfamily of the major facilitator superfamily, and both catalyze sugar/H(+) symport across the cytoplasmic membrane. Thus far, there is no common substrate for the two permeases; CscB transports su...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201592y
更新日期:2011-12-27 00:00:00
abstract::Site-directed mutagenesis of the aspartate receptor of Salmonella typhimurium (Tars) at serine 68, a residue located within the aspartate binding pocket and at the subunit interface, identified this residue as an allosteric switch in this receptor. Substitutions at this position can affect both the type and degree of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961481v
更新日期:1996-11-26 00:00:00
abstract::Raman difference spectroscopy is used to probe the properties of a 36-nt RNA molecule, "D5", which lies at the heart of the catalytic apparatus in group II introns. For D5 that has all of its adenine residues labeled with (13)C and (15)N and utilizing Raman difference spectroscopy, we identify the conformationally sen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi902117w
更新日期:2010-04-27 00:00:00
abstract::Ribonuclease T1 was crystallized in the presence of vanadate(V). The crystal structure was solved by molecular replacement and refined by least-squares methods using stereochemical restraints. The refinement was based on data between 10 and 1.8 A and converged at a crystallographic R factor of 0.137. Except for the su...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00445a014
更新日期:1989-09-19 00:00:00
abstract::The p90 ribosomal S6 family of kinases (RSK) are potential drug targets, due to their involvement in cancer and other pathologies. There are currently only two known selective inhibitors of RSK, but the basis for selectivity is not known. One of these inhibitors is a naturally occurring kaempferol-α-L-diacetylrhamnosi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300620c
更新日期:2012-08-21 00:00:00
abstract::Kinetic and structural data are presented on the interaction with Torpedo californica acetylcholinesterase (TcAChE) of (+)-huperzine A, a synthetic enantiomer of the anti-Alzheimer drug, (-)-huperzine A, and of its natural homologue (-)-huperzine B. (+)-Huperzine A and (-)-huperzine B bind to the enzyme with dissociat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi020151+
更新日期:2002-09-03 00:00:00
abstract::The complete amino acid sequence of ragweed pollen allergen Ra3 has been determined. The molecule consists of 101 amino acid residues and to date is the only allergen isolated from Ambrosia elatior (short ragweed) which contains carbohydrate. This particular preparation of allergen has a single, unique amino acid sequ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00566a010
更新日期:1980-12-09 00:00:00
abstract::Cystathionine β-synthase (CBS) catalyzes the first step in the transsulfuration pathway in mammals, i.e., the condensation of serine and homocysteine to produce cystathionine and water. Recently, we have reported a steady-state kinetic analysis of the three hydrogen sulfide (H(2)S)-generating reactions that are cataly...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1010893
更新日期:2011-01-25 00:00:00
abstract::The mechanism of N-methyltryptophan oxidase, a flavin-dependent amine oxidase from Escherichia coli, was studied using a combination of kinetic isotope effects and theoretical calculations. The 15(kcat/Km) kinetic isotope effect for sarcosine oxidation is pH-dependent with a limiting value of 0.994-0.995 at high pH. D...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700482h
更新日期:2007-06-26 00:00:00
abstract::The rigor complexes that formed between rabbit skeletal muscle F-actin and chicken gizzard heavy meromyosin (HMM), in which the heavy chains had been cleaved with trypsin into 24K, 50K, and 68K fragments, were examined by using the zero-length chemical cross-linker 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC)...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00430a070
更新日期:1989-02-21 00:00:00
abstract::N,N'-dicyclohexylcarbodiimide (DCCD) has been reported to inhibit proton translocation by cytochrome bc(1) and b(6)f complexes without significantly altering the rate of electron transport, a process referred to as decoupling. To understand the possible role of DCCD in inhibiting the protonogenic reactions of cytochro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001482u
更新日期:2000-12-26 00:00:00