Abstract:
:A method has been developed for the routine synthesis of 2'(3')-o-monoacyl ribonucleoside 5'-diphosphates for stepwise synthesis of oligoribonucleotides with Escherichia coli polynucleotide phosphorylase. The use of triethyl orthoisovalerate allows the facile preparation of 2'(3')-o-isovaleryl-UDP, -CDP, -ADP, -GDP, -IDP, -EPLISON-APD, eplison-CDP, and N6-isopentenyl-ADP. The synthesis of N6-isopentenyl-ADP from ADP by N1-alkylation and the Dimroth rearrangement to N6 is reported. The effects of several factors including the nature of the divalent cation, pH, SALT CONCENTRATION, AND TIME ON THE EFFICIENCY OF THE POLYNUCLEOTIDE PHPSPHORYLASE CATALYZED SINGLE ADDITIONS OF THE 2'(3')-O-ISOVALERYL RIBONUCLEOSIDE 5'-DIPHOSPHATES TO AN OLIGORIBONUCLEOTIDE PRIMER ARE REPORTED. The syntheses of many tetranucleoside triphosphates and two pentanucleoside tetraphosphates in yields of 20-75 per cent are reported. The 2'(3')-o-isovaleryl derivatives of IDP, eplison-ADP, eplison-CDP, and N6-isopentenyl-ADP were all accepted by polynucleotide phosphorylase as substrates for the monoaddition reaction. The extension of the method to include the syntheses of oligoribonucleotides containing modified nucleosides offers a means of studying the role s of these modification by the use of relatively simple model compounds.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Walker GC,Uhlenbeck OCdoi
10.1021/bi00675a027subject
Has Abstractpub_date
1975-02-25 00:00:00pages
817-24issue
4eissn
0006-2960issn
1520-4995journal_volume
14pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::We have characterized the importance of size, sulfation, and anticoagulant activity of heparin in release of basic fibroblast growth factor (bFGF) from the subendothelial extracellular matrix (ECM) and the luminal surface of the vascular endothelium. For this purpose, 125I-bFGF was first incubated with ECM and conflue...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00122a027
更新日期:1992-02-25 00:00:00
abstract::Slow conformational changes have been proposed to be responsible for the kinetic positive cooperativity of glucokinase (GK) with glucose. Induced-fit and preexisting equilibrium kinetic models have been previously suggested. In the present study, equilibrium and pre-steady-state fluorescence spectroscopy has been used...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900374c
更新日期:2009-06-16 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::X-ray absorption spectra are reported for the multi-Cu oxidase Rhus vernicifera laccase in oxidized and fully reduced forms and for laccase from which the type 2 Cu has been depleted (T2D). The structure of the Cu K edge for both preparations shows the presence of CuII and CuI in the oxidized and reduced states, respe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00310a008
更新日期:1984-07-17 00:00:00
abstract::The effects of various ginsenosides on calmodulin-dependent phosphodiesterase isozymes have been investigated. Ginsenosides were found to be potent inhibitors of bovine heart calmodulin-dependent phosphodiesterase and the 60-kDa isozyme of bovine brain calmodulin-dependent phosphodiesterase but not of the 63-kDa isozy...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00070a001
更新日期:1993-05-18 00:00:00
abstract::The conformational conversion of prion protein (PrP) from an alpha-helix-rich normal cellular isoform (PrPC) to a beta-sheet-rich pathogenic isoform (PrPSc) is a key event in the development of prion diseases, and it takes place in caveolae, cavelike invaginations of the plasma membrane. A peptide homologous to residu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700939j
更新日期:2007-10-16 00:00:00
abstract::A rapid assay procedure was developed for cleavage of the N-terminal propeptides of procollagen. With the assay a neutral procollagen N-protease was purified about 300-fold from chick embryo tendon extract. The enzyme had an apparent molecular weight of 260 000 and a pH optimum of 7.4. Ca2+ was required for enzymic ac...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00608a002
更新日期:1978-07-25 00:00:00
abstract::Geobacillus stearothermophilus T-6 encodes for a beta-xylosidase (XynB2) from family 52 of glycoside hydrolases that was previously shown to hydrolyze its substrate with net retention of the anomeric configuration. XynB2 significantly prefers substrates with xylose as the glycone moiety and exhibits a typical bell-sha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034505o
更新日期:2003-09-09 00:00:00
abstract::The specificity of trypsin for Arg- and Lys-containing substrates depends upon the presence of Asp189 at the base of the primary binding pocket. The crystal structure of anionic rat trypsin D189S complexed with BPTI reveals that removal of the aspartate side chain permits the binding of a well-ordered acetate ion in a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00177a016
更新日期:1994-03-22 00:00:00
abstract::Ligand-dependent site-site (or subunit-subunit) interactions provide the basis for explaining cooperativity in chemical reactions. Even in the simplest possible nonaggregating system, interpretation of the interactions in terms of structural details requires an explicit assumption (or model) for the binding of the lig...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi00106a004
更新日期:1991-10-22 00:00:00
abstract::We have covalently attached an electron paramagnetic resonance (EPR) spin probe to Cys-670 of the motor domain of ncd (nonclaret disjunctional protein) in order to investigate conformational changes associated with the chemomechanical cycle. Spin-labeling is highly specific and does not affect ncd function as monitore...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9706881
更新日期:1997-08-12 00:00:00
abstract::The light-driven enzyme NADPH:protochlorophyllide oxidoreductase (POR) catalyzes the reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), a key regulatory step in the chlorophyll biosynthesis pathway. As POR is light activated, it allows intermediates in the reaction pathway to be observed by initiat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0268448
更新日期:2003-01-21 00:00:00
abstract::Cytochrome b5 reductase (cb5r), a member of the ferredoxin:NADP+ reductase family of flavoprotein transhydrogenases, catalyzes the NADH-dependent reduction of cytochrome b5. Within this family, a conserved "GxGxxP" sequence motif has been implicated in binding reduced pyridine nucleotides. However, Glycine 179, a cons...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051165t
更新日期:2005-10-18 00:00:00
abstract::The guanyl nucleotide binding regulatory protein of retinal rod outer segments, called Gt, that couples the photon receptor rhodopsin with the light-activated cGMP phosphodiesterase, can be resolved into two functional components, alpha t and beta gamma t. The effect of monoclonal antibody binding to the alpha t subun...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00451a047
更新日期:1989-12-12 00:00:00
abstract::The Cyt toxins produced by the bacteria Bacillus thuringiensis show insecticidal activity against some insects, mainly dipteran larvae, being able to kill mosquitoes and black flies. However, they also possess a general cytolytic activity in vitro, showing hemolytic activity in red blood cells. These proteins are comp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101239r
更新日期:2011-01-25 00:00:00
abstract::Peptides corresponding to portions of curaremimetic neurotoxin loop 2 and to a structurally similar segment of rabies virus glycoprotein were synthetically modified in order to gain information on structure-function relationships of neurotoxin loop 2 interactions with the acetylcholine receptor. Binding of synthetic p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00109a020
更新日期:1991-11-12 00:00:00
abstract::The conformational states of N-acylalanine dithio esters, involving rotational isomers about the RC(=O)NH--CH(CH3) and NHCH(CH3)--C(=S) bonds, are defined and compared to those of N-acylglycine dithio esters. The structure of N-(p-nitrobenzoyl)-DL-alanine ethyl dithio ester has been determined by X-ray crystallographi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00401a038
更新日期:1988-01-12 00:00:00
abstract::Several unique protein folds that catalyze the hydrolysis of phosphodiester bonds have arisen independently in nature, including the PD(D/E)XK superfamily (typified by type II restriction endonucleases and many recombination and repair enzymes) and the HNH superfamily (found in an equally wide array of enzymes, includ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700418d
更新日期:2007-06-19 00:00:00
abstract::The human endonuclease III homologue (hNTH1) removes premutagenic cytosine damage from DNA. This includes 5-hydroxycytosine, which has increased potential for pairing with adenine, resulting in C --> T transition mutations. Here we report that hNTH1 acts on both 5-hydroxycytosine and abasic sites preferentially when t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0028901
更新日期:2001-06-05 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::The alpha-conotoxins MI and GI display stronger affinities for the alphagamma agonist site on the Torpedo californica electrocyte nicotinic acetylcholine receptor (ACHR) than for the alphadelta agonist site, while alpha-conotoxin SI binds with the same affinity to both sites. Prior studies reported that the arginine a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi030248b
更新日期:2004-10-05 00:00:00
abstract::As part of a search for peptides that have specificity for selected protein kinases, the possibility that adenosine cyclic 3',5'-phosphate dependent protein kinase (A-kinase) recognizes the hydrogen-bonding potential of its peptide substrates was investigated. A-Kinase catalyzes the phosphorylation of five N alpha-met...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00388a041
更新日期:1987-07-14 00:00:00
abstract::M proteins and other members of the M protein family, expressed on the surface of Streptococcus pyogenes, bind host proteins such as immunoglobulins, albumin, and fibrinogen. Protein H and the M1 protein are expressed by adjacent genes and both belong to the M protein family. In this work, the structure and stability ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00041a051
更新日期:1995-10-17 00:00:00
abstract::Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found, for example, in such macrolide antibiotics as erthyromycin, azithromycin, and clarithromycin. The efficacies of these macrolide antibiotics are markedly reduced in the absence of desosamine. In the bacterium Streptomyces venezuelae, six enzymes are required...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700751d
更新日期:2007-08-07 00:00:00
abstract::Conformational selection and induced fit are two well-known mechanisms of allosteric protein-ligand interaction. Some proteins, like ubiquitin, have recently been found to exist in multiple conformations at equilibrium, suggesting that the conformational selection may be a general mechanism of interaction, in particul...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900559k
更新日期:2009-08-04 00:00:00
abstract::The conformational change of the model peptide Ac-K-G-R-G-D-G-amide induced by a phospholipidic interface was investigated by proton nuclear magnetic resonance (1H NMR). In aqueous solution, the free peptide is highly flexible and disordered, even in the presence of deuterated dodecyl-phosphocholine (DPC-d38) micelles...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00124a018
更新日期:1992-03-10 00:00:00
abstract::By use of six highly purified exoglycosidases with well-defined specificity, the oligosaccharide units of human plasma beta 2-glycoprotein I (beta 2I) were modified by sequential enzymatic degradation. The released monosaccharides (NeuAc, Gal, GlcNAc, and Man) were quantified, and the carbohydrate compositions of the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00478a020
更新日期:1990-07-03 00:00:00
abstract::Site-directed mutagenesis has been used to construct three recombinant mutant hemoglobins (rHbs), rHb(beta L105W), rHb(alpha D94A/betaL105W), and rHb(alpha D94A). rHb(beta L105W) is designed to form a new hydrogen bond from beta 105Trp to alpha 94Asp in the alpha(1)beta(2) subunit interface to lower the oxygen binding...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001115i
更新日期:2000-11-14 00:00:00
abstract::Antimicrobial peptides (AMPs) are important components of the host innate immune system. Papiliocin is a 37-residue AMP purified from larvae of the swallowtail butterfly Papilio xuthus. Magainin 2 is a 23-residue AMP purified from the skin of the African clawed frog Xenopus laevis. We designed an 18-residue hybrid pep...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00392
更新日期:2015-06-30 00:00:00
abstract::Cofilin is an actin regulatory protein that binds to both monomeric and filamentous actin, and has filament severing activity. Although crystal structures for the monomeric forms of both G-actin and cofilin have been described, the structure of the binary cofilin-G-actin complex is not available. Synchrotron protein f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0121104
更新日期:2002-05-07 00:00:00