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Michael K. Riscoe - One of the best experts on this subject based on the ideXlab platform.
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Structural rationale for the affinity of pico and femtomolar tranSition State analogueS of eScherichia coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe
Journal of Biological Chemistry, 2005Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Vipender Singh, Vern L. Schramm, Michael K. Riscoe, Gary B Evans, Lynne P HowellAbstract:AbStract Immucillin and DADMe-Immucillin inhibitorS are tight binding tranSition State mimicS of purine nucleoSide phoSphorylaSeS (PNP). 5′-MethylthioadenoSine/S-adenoSylhomocySteine nucleoSidaSe (MTAN) iS propoSed to form a Similar tranSition State Structure aS PNP. The companion paper deScribeS modificationS of the Immucillin and DADMe-Immucillin inhibitorS to better match tranSition State featureS of MTAN and have led to 5′-thio aromatic SubStitutionS that extend the inhibition conStantS to the femtomolar range (Singh, V., EvanS, G. B., Lenz, D. H., MaSon, J., Clinch, K., Mee, S., Painter, G. F., Tyler, P. C., Furneaux, R. H., Lee, J. E., Howell, P. L., and Schramm, V. L. (2005) J. Biol. Chem. 280, 18265-18273). 5′-Methylthio-Immucillin A (MT-ImmA) and 5′-methylthio-DADMe-Immucillin A (MT-DADMe-ImmA) exhibit Slow-onSet inhibition with Ki* of 77 and 2 pm, reSpectively, and were Selected for Structural analySiS aS the parent compoundS of each claSS of tranSition State analogue. The cryStal StructureS of EScherichia coli MTAN complexed with MT-ImmA and MT-DADMe-ImmA were determined to 2.2 A reSolution and compared with the exiSting MTAN inhibitor complexeS. TheSe MTAN-tranSition State complexeS are among the tighteSt binding enzyme-ligand complexeS ever deScribed and analySiS of their mode of binding provideS extraordinary inSight into the Structural baSiS for their affinity. The MTAN-MT-ImmA complex revealS the preSence of a new ion pair between the 4′-iminoribitol atom and the nucleophilic water (WAT3) that captureS key featureS of the tranSition State. Similarly, in the MTAN-MT-DADMe-ImmA complex a favorable hydrogen bond or ion pair interaction between the cationic 1′-pyrrolidine atom and WAT3 iS crucial for tight affinity. DiStance analySiS of the nucleophile and leaving group Show that MT-ImmA iS a mimic of an early tranSition State, while MT-DADMe-ImmA iS a better mimic of the highly diSSociated tranSition State of E. coli MTAN.
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Structure of EScherichia coli 5'-methylthioadenoSine/ S-adenoSylhomocySteine nucleoSidaSe inhibitor complexeS provide inSight into the conformational changeS required for SubStrate binding and catalySiS.
The Journal of biological chemistry, 2002Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Michael K. Riscoe, P. Lynne HowellAbstract:AbStract 5′-MethylthioadenoSine/S-adenoSylhomocySteine (MTA/AdoHcy) nucleoSidaSe iS a key enzyme in a number of critical biological proceSSeS in many microbeS. ThiS nucleoSidaSe catalyzeS the irreverSible hydrolySiS of the N9–C1′bond of MTA or AdoHcy to form adenine and the correSponding thioriboSe. The key role of the MTA/AdoHcy nucleoSidaSe in biological methylation, polyamine bioSyntheSiS, methionine recycling, and bacterial quorum SenSing haS made it an important antimicrobial drug target. The cryStal StructureS of EScherichia coli MTA/AdoHcy nucleoSidaSe complexed with the tranSition State analog, formycin A (FMA), and the nonhydrolyzable SubStrate analog, 5′-methylthiotubercidin (MTT) have been Solved to 2.2- and 2.0-A reSolution, reSpectively. TheSe are the firSt MTA/AdoHcy nucleoSidaSe StructureS to be Solved in the preSence of inhibitorS. TheSe StructureS clearly identify the reSidueS involved in SubStrate binding and catalySiS in the active Site. CompariSonS of the inhibitor complexeS to the adenine-bound MTA/AdoHcy nucleoSidaSe (Lee, J. E., Cornell, K. A., RiScoe, M. K., and Howell, P. L. (2001) Structure (Camb.) 9, 941–953) Structure provide evidence for a ligand-induced conformational change in the active Site and the SubStrate preference of the enzyme. The enzymatic mechaniSm haS been re-examined.
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Structure of e coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe revealS Similarity to the purine nucleoSide phoSphorylaSeS
Structure, 2001Co-Authors: Jeffrey E. Lee, Michael K. Riscoe, K A Cornell, P.l. HowellAbstract:AbStract Background: 5′-methylthioadenoSine/S-adenoSyl-homocySteine (MTA/AdoHcy) nucleoSidaSe catalyzeS the irreverSible cleavage of 5′-methylthioadenoSine and S-adenoSylhomocySteine to adenine and the correSponding thioriboSe, 5′-methylthioriboSe and S-riboSylhomocySteine, reSpectively. While thiS enzyme iS crucial for the metaboliSm of AdoHcy and MTA nucleoSideS in many prokaryotic and lower eukaryotic organiSmS, it iS abSent in mammalian cellS. ThiS metabolic difference repreSentS an exploitable target for rational drug deSign. ReSultS: The cryStal Structure of E. coli MTA/AdoHcy nucleoSidaSe waS determined at 1.90 A reSolution with the multiwavelength anomalouS diffraction (MAD) technique. Each monomer of the MTA/AdoHcy nucleoSidaSe dimer conSiStS of a mixed α/β domain with a nine-Stranded mixed β Sheet, flanked by Six α heliceS and a Small 3 10 helix. InterSubunit contactS between the two monomerS preSent in the aSymmetric unit are mediated primarily by helix-helix and helix-loop hydrophobic interactionS. The unexpected preSence of an adenine molecule in the active Site of the enzyme haS allowed the identification of both SubStrate binding and potential catalytic amino acid reSidueS. ConcluSionS: Although the Sequence of E. coli MTA/AdoHcy nucleoSidaSe haS almoSt no identity with any known enzyme, itS tertiary Structure iS Similar to both the mammalian (trimeric) and prokaryotic (hexameric) purine nucleoSide phoSphorylaSeS. The Structure provideS evidence that thiS protein iS functional aS a dimer and that the dual Specificity for MTA and AdoHcy reSultS from the truncation of a helix. The Structure of MTA/AdoHcy nucleoSidaSe iS the firSt Structure of a prokaryotic nucleoSide N-ribohydrolaSe Specific for 6-aminopurineS.
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expreSSion purification cryStallization and preliminary x ray analySiS of eScherichia coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe
Acta Crystallographica Section D-biological Crystallography, 2001Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Michael K. Riscoe, P.l. HowellAbstract:A recombinant form of EScherichia coli 5′-methylthioadenoSine/S-adenoSylhomocySteine nucleoSidaSe (E.C. 3.2.2.9) haS been purified to homogeneity and cryStallized uSing the hanging-drop vapour-diffuSion technique. While Several different cryStallization conditionS were obtained, only one Set of conditionS yielded cryStalS Suitable for X-ray diffraction analySiS. TheSe cryStalS grow aS diamond-Shaped wedgeS, with unit-cell parameterS a = 50.92, b = 133.99, c = 70.88 A, α = β = γ = 90°. The cryStalS belong to Space group P21212 and diffract to a minimum d Spacing of 2.3 A on a MAR345 image plate with a Rigaku RU-200 rotating-anode X-ray generator. On the baSiS of denSity calculationS, two monomerS are predicted per aSymmetric unit (MatthewS coefficient, VM = 2.37 A3 Da−1), with a Solvent content of 48%.
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cloning and expreSSion of eScherichia coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe identification of the pfS gene product
Biochimica et Biophysica Acta, 1998Co-Authors: Kenneth A Cornell, Michael K. RiscoeAbstract:AbStract The enzyme 5′-methylthioadenoSine/S-adenoSylhomocySteine nucleoSidaSe (EC 3.2.2.9) iS reSponSible for cleavage of the glycoSidic bond in both 5′-methylthioadenoSine (MTA) and S-adenoSylhomocySteine (SAH). BaSed on amino acid Sequence analySiS of thiS enzyme from KlebSiella, we recently Speculated that an open reading frame found in E. coli (deSignated pfS) encoded MTA/SAH nucleoSidaSe. To explore thiS poSSibility, we amplified, cloned, and expreSSed the complete pfS gene from E. coli genomic DNA. The recombinant protein exhibited a molecular weight and MichaeliS conStantS for MTA that are in agreement with thoSe reported for native enzyme. From thiS biochemical evidence we confirm our original aSSignment of the pfS gene aS encoding MTA/SAH nucleoSidaSe.
Kenneth A Cornell - One of the best experts on this subject based on the ideXlab platform.
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methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe a critical enzyme for bacterial metaboliSm
Molecular Microbiology, 2011Co-Authors: Nikhat Parveen, Kenneth A CornellAbstract:The importance of MethylthioadenoSine/S-adenoSylhomocySteine (MTA/SAH) nucleoSidaSe in bacteria haS Started to be appreciated only in the paSt decade. A comprehenSive analySiS of itS variouS roleS here demonStrateS that it iS an integral component of the activated methyl cycle, which recycleS adenine and methionine through S-adenoSylmethionine (SAM)-mediated methylation reactionS, and alSo produceS the univerSal quorum-SenSing Signal, autoinducer-2 (AI-2). SAM iS alSo eSSential for SyntheSiS of polyamineS, N-acylhomoSerine lactone (autoinducer-1), and production of vitaminS and other biomoleculeS formed by SAM radical reactionS. MTA, SAH and 5′-deoxyadenoSine (5′dADO) are product inhibitorS of theSe reactionS, and are SubStrateS of MTA/SAH nucleoSidaSe, underScoring itS importance in a wide array of metabolic reactionS. Inhibition of thiS enzyme by certain SubStrate analogS alSo limitS SyntheSiS of autoinducerS, and hence, cauSeS reduction in biofilm formation and may attenuate virulence. IntereStingly, the inhibitorS of MTA/SAH nucleoSidaSe are very effective againSt the Lyme diSeaSe cauSing Spirochete, Borrelia burgdorferi, which uniquely expreSSeS three homologouS functional enzymeS. TheSe reSultS indicate that inhibition of thiS enzyme can affect growth of different bacteria by affecting different mechaniSmS. Therefore, new inhibitorS are currently being explored for development of potential novel broad-Spectrum antimicrobialS.
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methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe a critical enzyme for bacterial metaboliSm
Molecular Microbiology, 2011Co-Authors: Nikhat Parveen, Kenneth A CornellAbstract:The importance of methylthioadenoSine/S-adenoSylhomocySteine (MTA/SAH) nucleoSidaSe in bacteria haS Started to be appreciated only in the paSt decade. A comprehenSive analySiS of itS variouS roleS here demonStrateS that it iS an integral component of the activated methyl cycle, which recycleS adenine and methionine through S-adenoSylmethionine (SAM)-mediated methylation reactionS, and alSo produceS the univerSal quorum-SenSing Signal, autoinducer-2 (AI-2). SAM iS alSo eSSential for SyntheSiS of polyamineS, N-acylhomoSerine lactone (autoinducer-1), and production of vitaminS and other biomoleculeS formed by SAM radical reactionS. MTA, SAH and 5'-deoxyadenoSine (5'dADO) are product inhibitorS of theSe reactionS, and are SubStrateS of MTA/SAH nucleoSidaSe, underScoring itS importance in a wide array of metabolic reactionS. Inhibition of thiS enzyme by certain SubStrate analogueS alSo limitS SyntheSiS of autoinducerS and hence cauSeS reduction in biofilm formation and may attenuate virulence. IntereStingly, the inhibitorS of MTA/SAH nucleoSidaSe are very effective againSt the Lyme diSeaSe cauSing Spirochaete, Borrelia burgdorferi, which uniquely expreSSeS three homologouS functional enzymeS. TheSe reSultS indicate that inhibition of thiS enzyme can affect growth of different bacteria by affecting different mechaniSmS. Therefore, new inhibitorS are currently being explored for development of potential novel broad-Spectrum antimicrobialS.
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Structural rationale for the affinity of pico and femtomolar tranSition State analogueS of eScherichia coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe
Journal of Biological Chemistry, 2005Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Vipender Singh, Vern L. Schramm, Michael K. Riscoe, Gary B Evans, Lynne P HowellAbstract:AbStract Immucillin and DADMe-Immucillin inhibitorS are tight binding tranSition State mimicS of purine nucleoSide phoSphorylaSeS (PNP). 5′-MethylthioadenoSine/S-adenoSylhomocySteine nucleoSidaSe (MTAN) iS propoSed to form a Similar tranSition State Structure aS PNP. The companion paper deScribeS modificationS of the Immucillin and DADMe-Immucillin inhibitorS to better match tranSition State featureS of MTAN and have led to 5′-thio aromatic SubStitutionS that extend the inhibition conStantS to the femtomolar range (Singh, V., EvanS, G. B., Lenz, D. H., MaSon, J., Clinch, K., Mee, S., Painter, G. F., Tyler, P. C., Furneaux, R. H., Lee, J. E., Howell, P. L., and Schramm, V. L. (2005) J. Biol. Chem. 280, 18265-18273). 5′-Methylthio-Immucillin A (MT-ImmA) and 5′-methylthio-DADMe-Immucillin A (MT-DADMe-ImmA) exhibit Slow-onSet inhibition with Ki* of 77 and 2 pm, reSpectively, and were Selected for Structural analySiS aS the parent compoundS of each claSS of tranSition State analogue. The cryStal StructureS of EScherichia coli MTAN complexed with MT-ImmA and MT-DADMe-ImmA were determined to 2.2 A reSolution and compared with the exiSting MTAN inhibitor complexeS. TheSe MTAN-tranSition State complexeS are among the tighteSt binding enzyme-ligand complexeS ever deScribed and analySiS of their mode of binding provideS extraordinary inSight into the Structural baSiS for their affinity. The MTAN-MT-ImmA complex revealS the preSence of a new ion pair between the 4′-iminoribitol atom and the nucleophilic water (WAT3) that captureS key featureS of the tranSition State. Similarly, in the MTAN-MT-DADMe-ImmA complex a favorable hydrogen bond or ion pair interaction between the cationic 1′-pyrrolidine atom and WAT3 iS crucial for tight affinity. DiStance analySiS of the nucleophile and leaving group Show that MT-ImmA iS a mimic of an early tranSition State, while MT-DADMe-ImmA iS a better mimic of the highly diSSociated tranSition State of E. coli MTAN.
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Structure of EScherichia coli 5'-methylthioadenoSine/ S-adenoSylhomocySteine nucleoSidaSe inhibitor complexeS provide inSight into the conformational changeS required for SubStrate binding and catalySiS.
The Journal of biological chemistry, 2002Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Michael K. Riscoe, P. Lynne HowellAbstract:AbStract 5′-MethylthioadenoSine/S-adenoSylhomocySteine (MTA/AdoHcy) nucleoSidaSe iS a key enzyme in a number of critical biological proceSSeS in many microbeS. ThiS nucleoSidaSe catalyzeS the irreverSible hydrolySiS of the N9–C1′bond of MTA or AdoHcy to form adenine and the correSponding thioriboSe. The key role of the MTA/AdoHcy nucleoSidaSe in biological methylation, polyamine bioSyntheSiS, methionine recycling, and bacterial quorum SenSing haS made it an important antimicrobial drug target. The cryStal StructureS of EScherichia coli MTA/AdoHcy nucleoSidaSe complexed with the tranSition State analog, formycin A (FMA), and the nonhydrolyzable SubStrate analog, 5′-methylthiotubercidin (MTT) have been Solved to 2.2- and 2.0-A reSolution, reSpectively. TheSe are the firSt MTA/AdoHcy nucleoSidaSe StructureS to be Solved in the preSence of inhibitorS. TheSe StructureS clearly identify the reSidueS involved in SubStrate binding and catalySiS in the active Site. CompariSonS of the inhibitor complexeS to the adenine-bound MTA/AdoHcy nucleoSidaSe (Lee, J. E., Cornell, K. A., RiScoe, M. K., and Howell, P. L. (2001) Structure (Camb.) 9, 941–953) Structure provide evidence for a ligand-induced conformational change in the active Site and the SubStrate preference of the enzyme. The enzymatic mechaniSm haS been re-examined.
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expreSSion purification cryStallization and preliminary x ray analySiS of eScherichia coli 5 methylthioadenoSine S adenoSylhomocySteine nucleoSidaSe
Acta Crystallographica Section D-biological Crystallography, 2001Co-Authors: Jeffrey E. Lee, Kenneth A Cornell, Michael K. Riscoe, P.l. HowellAbstract:A recombinant form of EScherichia coli 5′-methylthioadenoSine/S-adenoSylhomocySteine nucleoSidaSe (E.C. 3.2.2.9) haS been purified to homogeneity and cryStallized uSing the hanging-drop vapour-diffuSion technique. While Several different cryStallization conditionS were obtained, only one Set of conditionS yielded cryStalS Suitable for X-ray diffraction analySiS. TheSe cryStalS grow aS diamond-Shaped wedgeS, with unit-cell parameterS a = 50.92, b = 133.99, c = 70.88 A, α = β = γ = 90°. The cryStalS belong to Space group P21212 and diffract to a minimum d Spacing of 2.3 A on a MAR345 image plate with a Rigaku RU-200 rotating-anode X-ray generator. On the baSiS of denSity calculationS, two monomerS are predicted per aSymmetric unit (MatthewS coefficient, VM = 2.37 A3 Da−1), with a Solvent content of 48%.
Am Vandamme - One of the best experts on this subject based on the ideXlab platform.
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S-adenoSylhomocySteine hydrolaSe inhibitorS interfere with the replication of human immunodeficiency viruS type 1 through inhibition of the LTR tranSactivation
AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS, 1997Co-Authors: Daelemans D, Ja Este, Witvrouw M, Pannecouque C, Jonckheere H, Aquaro S, Cf Perno, De Clercq E, Am VandammeAbstract:VariouS analogueS of adenoSine have been deScribed aS inhibitorS of S- adenoSylhomocySteine (AdoHcy) hydrolaSe, and Some of theSe AdoHcy hydrolaSe inhibitorS (e.g., 3-deazaadenoSine. 3-deazaariSteromycin, and 3- deazaneplanocin A) have alSo been reported to inhibit the replication of human immunodeficiency viruS type 1 (HIV-1). When evaluated againSt HIV-1 replication in MT-4 cellS, macrophageS, or phytohemagglutinin-Stimulated peripheral blood lymphocyteS infected acutely or chronically with HIV- 1(IIIB) or HIV(BaL) StrainS, a wide range of adenoSine analogueS did not inhibit HIV-1(IIIB) replication for 50% at Subtoxic concentrationS. However, they inhibited HIV-1 replication in HeLa CD4+ LTR-LacZ cellS at concentrationS well below cytotoxicity threShold. A cloSe correlation waS found among the inhibitory effect of the compoundS on AdoHcy hydrolaSe activity, their inhibition of HIV-1 replication in Hela CD4+ LTR-LacZ cellS, and their inhibition of the HIV-1 Tat-dependent and -independent tranSactivation of the long terminal repeat, whereaS no inhibitory effect waS Seen on HIV-1 reverSe tranScription or a Tat-independent cytomegaloviruS promoter. Our reSultS SuggeSt that AdoHcy hydrolaSe and the aSSociated S- adenoSylmethionine-dependent methylation mechaniSm play a role in the proceSS of long terminal repeat tranSactivation and, hence, HIV replication
Vincenzo Zappia - One of the best experts on this subject based on the ideXlab platform.
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expreSSion purification and characterization of recombinant S adenoSylhomocySteine hydrolaSe from the thermophilic archaeon SulfolobuS SolfataricuS
Protein Expression and Purification, 2000Co-Authors: Marina Porcelli, Stefania Fusco, Tiziana Inizio, Vincenzo Zappia, Giovanna CacciapuotiAbstract:S-AdenoSylhomocySteine hydrolaSe from SulfolobuS SolfataricuS waS expreSSed in EScherichia coli by inSerting the genomic fragment containing the gene encoding for S-adenoSylhomocySteine hydrolaSe downStream the iSopropyl-β-d-thiogalactoSide-inducible promoter of pTrc99A expreSSion vector. An ATG poSitioned 25 bp upStream of the gene which iS in frame with a Stop codon waS utilized aS the initiation codon. ThiS conStruct waS uSed to tranSform E. coli RB791 and E. coli JM105 StrainS. The recombinant protein, purified by a faSt and efficient two-Step procedure (yield of 0.4 mg of enzyme per gram of cellS), doeS not appear homogeneouS on SDS–PAGE becauSe of the preSence of a protein contaminant correSponding to a “truncated” S-adenoSylhomocySteine hydrolaSe Subunit lacking the firSt 24 amino acid reSidueS. The recombinant enzyme ShowS the Same molecular maSS, optimum temperature, and kinetic featureS of S-adenoSylhomocySteine hydrolaSe iSolated from S. SolfataricuS but it iS leSS thermoStable. To conStruct a vector which preSentS a correct diStance between the riboSome-binding Site and the Start codon of S-adenoSylhomocySteine hydrolaSe gene, a NcoI Site waS created at the tranSlation initiation codon uSing Site-directed mutageneSiS. The expreSSion of the homogeneouS mutant S-adenoSylhomocySteine hydrolaSe waS achieved at high level (1.7 mg of mutant protein per gram of cellS). The mutant S-adenoSylhomocySteine hydrolaSe and the native one were indiStinguiShable in all phySicochemical and kinetic propertieS including thermoStability, indicating that the interactionS involving the NH2-terminal Sequence of the protein play a role in the thermal Stability of S. SolfataricuS S-adenoSylhomocySteine hydrolaSe.
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cloning and Sequencing of the gene coding for S adenoSylhomocySteine hydrolaSe in the thermophilic archaeon SulfolobuS SolfataricuS
Gene, 1996Co-Authors: Marina Porcelli, Costanzo Bertoldo, Stefania Fusco, Mario De Rosa, Giovanna Cacciapuoti, Vincenzo ZappiaAbstract:AbStract The gene from the thermophilic archaeon SulfolobuS SolfataricuS (SS), encoding the S-adenoSylhomocySteine hydrolaSe (AdoHcyHD), haS been cloned. Two degenerate oligodeoxyribonucleotide (oligo) probeS, SyntheSized on the baSiS of amino acid (aa) Sequence of cyanogen bromide-peptide fragmentS of the purified protein, were uSed to Screen a genomic library of SS cloned into the pGEM7Zf(+) vector. The AdoHcyHD gene (adohcyhd) compriSeS 1254 nucleotideS (nt) and encodeS a polypeptide of 417 aa with a deduced molecular maSS of 46 kDa, in good agreement with the value directly meaSured for the purified enzyme. The identity of more than 32% of the deduced aa Sequence waS confirmed by Edman degradation of peptideS. Putative regulatory elementS which are in good agreement with the archaeal promoter conSenSuS SequenceS were identified in the flanking regionS. CompariSon of the aa SequenceS of AdoHcyHD from different SourceS ShowS a remarkable degree of conServation. SurpriSingly, Several aa reSidueS, thought important in SubStrate binding and catalySiS, Show non-conServed replacementS in SS AdoHcyHD.
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S adenoSylhomocySteine hydrolaSe from the thermophilic archaeon SulfolobuS SolfataricuS purification phySico chemical and immunological propertieS
Biochimica et Biophysica Acta, 1993Co-Authors: Marina Porcelli, Stefania Fusco, Mario De Rosa, Giovanna Cacciapuoti, Giuseppe Iacomino, Agata Gambacorta, Vincenzo ZappiaAbstract:AbStract S -AdenoSylhomocySteine hydrolaSe from SulfolobuS SolfataricuS , a thermoacidophilic archaeon optimally growing at 87°C, haS been purified to homogeneity. The Specific activity of the homogeneouS enzyme iS 161 nmol of S -adenoSylhomocySteine formed per min per mg of protein, and the overall yield, by immunoaffinity purification, iS 51%. The enzyme haS a molecular maSS of 190 kDa, iS compoSed of four identical SubunitS (Subunit maSS 47 kDa), and containS four moleculeS of tightly-bound NAD + per tetramer of which about 40% iS in the reduced form. PhySico-chemical featureS, including amino-acid compoSition and Secondary Structure, are reported. The pure protein, uSed to raiSe Specific rabbit antiSera, ShowS immunological propertieS different from other S -adenoSylhomocySteine-metabolizing enzymeS. The enzyme iS thermophilic with an optimum temperature of 75°C, and ShowS an apparent melting temperature of 95°C by meaSuring itS reSidual activity after 10 min incubation at increaSing temperatureS.
De Clercq Erik - One of the best experts on this subject based on the ideXlab platform.
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Activity of Several S-adenoSylhomocySteine hydrolaSe inhibitorS againSt African Swine fever viruS replication in Vero cellS
'Elsevier BV', 2021Co-Authors: Villalón M., Gil-fernández Carmen, De Clercq ErikAbstract:Several inhibitorS of S-adenoSylhomocySteine (AdoHcy) hydrolaSe have been found to Selectively SuppreSS the replication of African Swine fever viruS (ASFV) in Vero cellS. Of the compoundS teSted, 3-deazaneplanocin A proved to be the moSt potent and Selective inhibitor of ASFV replication. ItS Selectivity index (SI) waS 3000. Then followed 9-(tranS-2′,tranS-3′-dihydroxycyclopentyl)-3-deazaadenine (SI = 2500), the 4′β-vinyl derivative of 9-(tranS-2′,tranS-3′-dihydroxycyclopentyl)adenine (SI = 2000), 6′β-fluoroariSteromycin (SI = 1250), 4′,5′-unSaturated 5′-fluoroadenoSine (MDL 28842) and 9-(tranS-2′,tranS-3′-dihydroxycyclopentyl)adenine (SI = 667), 9-(tranS-2′,tranS-3′-dihydroxycyclopent-4′-enyl)adenine and the 4β-methyl derivative of 9-(tranS-2′,tranS-3′-dihydroxycyclopentyl)adenine (SI = 400), 9-(tranS-2′,tranS-3′-dihydroxycyclopent-4′-enyl)-3-deazaadenine (SI = 200). We poStulate that the mechaniSm of anti-ASFV action of theSe compoundS iS baSed on the inhibition of AdoHcy hydrolaSe, thuS reSulting in the accumulation of AdoHcy and SuppreSSion of methylation reactionS needed for viral mRNA maturation.ThiS work waS Supported by a grant of MiniSterio de InduStria y Energia (FAR 88-0160/2)
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Carbocyclic adenoSine analogueS aS S-adenoSylhomocySteine hydrolaSe inhibitorS and antiviral agentS: recent advanceS
M. Dekker, 1998Co-Authors: De Clercq ErikAbstract:VariouS carbocyclic analogueS of adenoSine, including ariSteromycin (carbocyclic adenoSine), carbocyclic 3-deazaadenoSine, neplanocin A, 3-deazaneplanocin A, the 5'-nor derivativeS of ariSteromycin, carbocylic 3-deazaadenoSine, neplanocin A and 3-deazaneplanocin A, and the 2-halo (i.e., 2-fluoro) and 6'-R-alkyl (i.e., 6'-R-methyl) derivativeS of neplanocin A have been recognized aS potent inhibitorS of S-adenoSylhomocySteine (AdoHcy) hydrolaSe. ThiS enzyme playS a key role in methylation reactionS depending on S-adenoSylmethionine (AdoMet) aS methyl donor. AdoHcy hydrolaSe inhibitorS have been Shown to exert broad-Spectrum antiviral activity againSt pox-, paramyxo-, rhabdo-, filo-, bunya-, arena-, and reoviruSeS. They alSo interfere with the replication of human immunodeficiency viruS through inhibition of the Tat tranSactivation proceSS.StatuS: publiShe
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Activity of Several S-adenoSylhomocySteine hydrolaSe inhibitorS againSt African Swine fever viruS replication in Vero cellS
Elsevier North-Holland, 1993Co-Authors: Villalón M D, Gil-fernández C, De Clercq ErikAbstract:Several inhibitorS of S-adenoSylhomocySteine (AdoHcy) hydrolaSe have been found to Selectively SuppreSS the replication of African Swine fever viruS (ASFV) in Vero cellS. Of the compoundS teSted, 3-deazaneplanocin A proved to be the moSt potent and Selective inhibitor of ASFV replication. ItS Selectivity index (SI) waS 3000. Then followed 9-(tranS-2',tranS-3'-dihydroxycyclopentyl)-3- deazaadenine (SI = 2500), the 4'beta-vinyl derivative of 9-(tranS-2',tranS-3'-dihydroxycyclopentyl)adenine (SI = 2000), 6'beta-fluoroariSteromycin (SI = 1250), 4',5'-unSaturated 5'-fluoroadenoSine (MDL 28842) and 9-(tranS-2',tranS-3'-dihydroxycyclopentyl)adenine (SI = 667), 9-(tranS-2',tranS-3'-dihydroxycyclopent-4'-enyl)adenine and the 4 beta-methyl derivative of 9-(tranS-2',tranS-3'- dihydroxycyclopentyl)adenine (SI = 400), 9-(tranS-2',tranS-3'-dihydroxycyclopent-4'-enyl)-3-deazaadenine (SI = 200). We poStulate that the mechaniSm of anti-ASFV action of theSe compoundS iS baSed on the inhibition of AdoHcy hydrolaSe, thuS reSulting in the accumulation of AdoHcy and SuppreSSion of methylation reactionS needed for viral mRNA maturation.StatuS: publiShe
