Research Topics
Genomes and Genes | Robert PhillipsSummaryAffiliation: University of Georgia Country: USA Publications
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Publications
Conformational changes and loose packing promote E. coli Tryptophanase cold labilityAnna Kogan
Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel
BMC Struct Biol 9:65. 2009..This sequence of events is termed cold lability and its understanding bears relevance to protein stability and shelf life...- Differential effects of temperature and hydrostatic pressure on the formation of quinonoid intermediates from L-Trp and L-Met by H463F mutant Escherichia coli tryptophan indole-lyaseRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602 2556, USA
Biochemistry 44:14289-97. 2005.... - Role of lysine-256 in Citrobacter freundii tyrosine phenol-lyase in monovalent cation activationRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602 2556, USA
Biochemistry 43:14412-9. 2004..Thus, Lys-256 is not the base which removes the alpha-proton during catalysis. The results show that the function of Lys-256 in TPL is in monovalent cation binding and activation... - Effects of hydrostatic pressure on the conformational equilibrium of tryptophan synthase from Salmonella typhimuriumRobert S Phillips
Department of Chemistry, University of Georgia, Athens, 30602, USA
Ann N Y Acad Sci 1189:95-103. 2010..The relaxation kinetics are also different if the P-jumps are made by increasing or decreasing pressure, suggesting that the enzyme conformations are ensembles of microstates... - Insights into the mechanism of Pseudomonas dacunhae aspartate beta-decarboxylase from rapid-scanning stopped-flow kineticsRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 49:5066-73. 2010..These results suggest that Arg-37, a conserved active site residue in ABDC, plays a role in modulating the pK(a) of the pyridoxal 5'-phosphate complexes during catalysis... - Aminoacrylate intermediates in the reaction of Citrobacter freundii tyrosine phenol-lyaseRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602 2556, USA
Biochemistry 45:9575-83. 2006..These results are the first direct spectroscopic observation of alpha-aminoacrylate intermediates in the reactions of TPL... - Quantitative effects of allosteric ligands and mutations on conformational equilibria in Salmonella typhimurium tryptophan synthaseRobert S Phillips
Department of Chemistry, University of Georgia, 1001 Cedar Street, Athens, GA 30602 2556, USA
Arch Biochem Biophys 470:8-19. 2008..These allosteric effects are finely tuned to control the synthesis of l-Trp without resulting in substrate or product inhibition... - Structure and mechanism of tryptophan indole-lyase and tyrosine phenol-lyaseRobert S Phillips
Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602, USA
Biochim Biophys Acta 1647:167-72. 2003..Thus, additional residues remote from the active site may be needed for substrate specificity. Both Trpase and TPL may react by a rare S(E)2-type mechanism... - Properties of tryptophan indole-lyase from a piezophilic bacterium, Photobacterium profundum SS9Robert S Phillips
Department of Chemistry, University of Georgia, Athens, GA 30602, USA
Arch Biochem Biophys 506:35-41. 2011..The results show that PpTrpase is adapted for optimal activity in the low temperature, high pressure marine environment... - Crystals of tryptophan indole-lyase and tyrosine phenol-lyase form stable quinonoid complexesRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
J Biol Chem 277:21592-7. 2002.... - Hydrostatic pressure affects the conformational equilibrium of Salmonella typhimurium tryptophan synthaseRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602 2556, USA
Biochemistry 44:7921-8. 2005..Thus, the open conformation has a smaller apparent net system volume than the closed conformation. We estimate that there are 35-47 more waters in the solvation shell of the open conformation than in that of the closed conformation... - Structure, mechanism, and substrate specificity of kynureninaseRobert S Phillips
Department of Chemistry, University of Georgia, Athens, GA 30602, USA
Biochim Biophys Acta 1814:1481-8. 2011..This article is part of a Special Issue entitled: Pyridoxal phosphate Enzymology... - Pressure and temperature jump relaxation kinetics of the conformational change in Salmonella typhimurium tryptophan synthase L-serine complex: large activation compressibility and heat capacity changes demonstrate the contribution of solvationRobert S Phillips
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
J Am Chem Soc 130:13580-8. 2008..6 to -4.4 kJ mol(-1) K(-1)). These changes are also consistent with large changes in solvation in the transition state for interconversion of external aldimine and aminoacrylate intermediates in the Tryptophan synthase-L-Ser complex... - The reaction of indole with the aminoacrylate intermediate of Salmonella typhimurium tryptophan synthase: observation of a primary kinetic isotope effect with 3-[(2)H]indoleMichael T Cash
Department of Chemistry, Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602-2556, USA
Arch Biochem Biophys 432:233-43. 2004.... - The crystal structure of the Pseudomonas dacunhae aspartate-beta-decarboxylase dodecamer reveals an unknown oligomeric assembly for a pyridoxal-5'-phosphate-dependent enzymeSantiago Lima
Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA 30602, USA
J Mol Biol 388:98-108. 2009..The mutagenesis results show that although Arg37 is not required for activity, it appears to be involved in the ABDC catalytic cycle... - Three-dimensional structure of kynureninase from Pseudomonas fluorescensCory Momany
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 43:1193-203. 2004..Unusual among PLP-dependent enzymes, Trp-256, which is also strictly conserved in kynureninases from bacteria to humans, donates a hydrogen bond to the phosphate through the indole N1-hydrogen... - Differential effects of bromination on substrates and inhibitors of kynureninase from Pseudomonas fluorescensChristian Heiss
Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
Org Biomol Chem 1:288-95. 2003..These results suggest that the binding modes of substrates and the various classes of inhibitors in the active site of kynureninase are different... - Kinetics and mechanism of superoxide reduction by two-iron superoxide reductase from Desulfovibrio vulgarisJoseph P Emerson
Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 41:4348-57. 2002.... - Histidine ligand protonation and redox potential in the rieske dioxygenases: role of a conserved aspartate in anthranilate 1,2-dioxygenaseZanna M Beharry
Department of Chemistry, Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 42:13625-36. 2003.... - Stopped-flow studies of the reaction of D-tartronate semialdehyde-2-phosphate with human neuronal enolase and yeast enolase 1John M Brewer
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, United States
FEBS Lett 584:979-83. 2010..Higher Mg2+ concentrations reduce the relative magnitude of the slower reaction. The results are interpreted in terms of a catalytically significant interaction between the two subunits of these enzymes... - Xerogel-encapsulated W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus performs asymmetric reduction of hydrophobic ketones in organic solventsMusa M Musa
Department of Chemistry, University of Georgia, 1001 Cedar St, Athens, GA 30602, USA
Angew Chem Int Ed Engl 46:3091-4. 2007 - Substituent effects on the reaction of beta-benzoylalanines with Pseudomonas fluorescens kynureninaseSunil Kumar
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 49:7913-9. 2010..These results provide additional evidence for a gem-diol intermediate in the catalytic mechanism of kynureninase... - Formation in vitro of hybrid dimers of H463F and Y74F mutant Escherichia coli tryptophan indole-lyase rescues activity with L-tryptophanRobert S Phillips
Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602 2556, USA
Biochemistry 41:4012-9. 2002.... - Excited state tautomerization of azaindoleMichael T Cash
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
Org Biomol Chem 3:3701-6. 2005..The polarity of the solvent helps to reduce the energy difference between the tautomers in the ground state by as much as 5.8 kcal mol(-1), but not enough to reverse the ground state tautomer preference... - Reaction of Pseudomonas fluorescens kynureninase with beta-benzoyl-L-alanine: detection of a new reaction intermediate and a change in rate-determining stepVijay B Gawandi
Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
Biochemistry 43:3230-7. 2004..V., Moore, J. A., III, Sundararaju, B., and Phillips, R. S. (1998) Biochemistry 37, 1376-1382], the rate-determining step in the reaction of beta-benzoyl-L-alanine with kynureninase is C(beta)-C(gamma) bond cleavage... - Detection of open and closed conformations of tryptophan synthase by 15N-heteronuclear single-quantum coherence nuclear magnetic resonance of bound 1-15N-L-tryptophanAndrew Osborne
Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
J Biol Chem 278:44083-90. 2003..In contrast, UV-visible spectra of wild-type and mutant Trp synthase in the presence of L-Trp with NaCl and/or disodium alpha-glycerophosphate are more difficult to interpret in terms of altered conformational equilibria... - Crystal structure of the Homo sapiens kynureninase-3-hydroxyhippuric acid inhibitor complex: insights into the molecular basis of kynureninase substrate specificitySantiago Lima
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
J Med Chem 52:389-96. 2009..The H102W/N333T and H102W/S332G/N333T mutants showed complete reversal of substrate specificity between 3-hydroxykynurenine and L-kynurenine, thus defining the primary residues contributing to substrate specificity in kynureninases... - Activity and selectivity of W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus in organic solvents and ionic liquids: mono- and biphasic mediaMusa M Musa
Department of Chemistry, University of Georgia, Athens, GA 30602 2556, USA
Org Biomol Chem 6:887-92. 2008..The enzyme showed high tolerance to both water-miscible and -immiscible solvents, which allows biotransformations to be conducted at high substrate concentrations... - 19F-NMR reveals metal and operator-induced allostery in MerRLingyun Song
Department of Microbiology, University of Georgia, Athens, GA 30602, USA
J Mol Biol 371:79-92. 2007.... - Crystal structure of Homo sapiens kynureninaseSantiago Lima
Departments of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
Biochemistry 46:2735-44. 2007..Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates... - Asymmetric reduction and oxidation of aromatic ketones and alcohols using W110A secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicusMusa M Musa
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
J Org Chem 72:30-4. 2007..R)-Alcohols, the anti-Prelog products, were obtained by enantiospecific oxidation of (S)-alcohols through oxidative kinetic resolution of the rac-alcohols using W110A TESADH in Tris buffer/acetone (90:10, v/v)... - Benzoate decreases the binding of cis,cis-muconate to the BenM regulator despite the synergistic effect of both compounds on transcriptional activationTodd J Clark
Departments of Microbiology. Chemistry, and Pharmaceutical. Biomedical Sciences, University of Georgia, Athens, Georgia 30602
J Bacteriol 186:1200-4. 2004..Similar results were obtained with truncated BenM lacking the DNA-binding domain. High-level transcriptional activation may require that some monomers within a BenM tetramer bind benzoate and others bind cis,cis-muconate... - A matrix-assisted laser desorption/ionization compatible reagent for tagging tryptophan residuesChunyan Li
Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
Eur J Mass Spectrom (Chichester, Eng) 12:213-21. 2006..Most significantly, it exhibits high photostability in MALDI-Fourier transform mass spectrometry analyses... - Kinetics of the superoxide reductase catalytic cycleJoseph P Emerson
Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, USA
J Biol Chem 278:39662-8. 2003..These results provide quantitative support for previous suggestions that, in times of oxidative stress, SORs efficiently divert intracellular reducing equivalents to superoxide... - Regioselective nitration of N(alpha),N(1)-bis(trifluoroacetyl)-L-tryptophan methyl ester: efficient synthesis of 2-nitro and 6-nitro-N-trifluoroacetyl-L-tryptophan methyl esterAndrew S Osborne
Department of Chemistry, University of Georgia, Athens, GA 30602, USA
Bioorg Med Chem Lett 18:5750-2. 2008.... - The design and synthesis of a selective inhibitor of fucosyltransferase VIM Carmen Galan
Complex Carbohydrate Research Center, University of Georgia, Athens 30602, USA
Org Biomol Chem 2:1376-80. 2004..However, it showed exquisite selectivity for inhibition of fucosyltransferase VI. The kinetic data support an unusual mechanism in which the inhibitor can bind to the GDP-fucose complex as well as another enzyme form... - Mass defect labeling of cysteine for improving peptide assignment in shotgun proteomic analysesHilda Hernandez
Department of Chemistry, University of Georgia, Athens, GA 30602, USA
Anal Chem 78:3417-23. 2006..This procedure permits the identification of proteins from the M. maripaludis proteome that are not usually observed by the standard protocol and shows that better protein coverage is obtained with this methodology... - Threonine-124 and phenylalanine-448 in Citrobacter freundii tyrosine phenol-lyase are necessary for activity with L-tyrosineTatyana V Demidkina
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
Biochem J 363:745-52. 2002..Phe-448 may be important to allow the formation of the closed conformation during the reaction... - Role of aspartate-133 and histidine-458 in the mechanism of tryptophan indole-lyase from Proteus vulgarisTatyana V Demidkina
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov Street, Moscow 119991, Russia
Biochemistry 42:11161-9. 2003..Asp-133 likely forms a hydrogen bond directly to the indole NH of the substrate, while His-458 probably is hydrogen bonded to Asp-133... - The role of acidic dissociation of substrate's phenol group in the mechanism of tyrosine phenol-lyaseNicolai G Faleev
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Street, Moscow 119991, Russia
Biochim Biophys Acta 1647:260-5. 2003..The reactivities of the two forms are quite comparable. The roles of catalytic groups in the active site, especially Arg381 and Thr-124, are discussed... - Ionization state of pyridoxal 5'-phosphate in D-serine dehydratase, dialkylglycine decarboxylase and tyrosine phenol-lyase and the influence of monovalent cations as inferred by 31P NMR spectroscopyKlaus D Schnackerz
Biozentrum der Universität Würzburg, Am Hubland, D 97074 Wurzburg, Germany
Biochim Biophys Acta 1764:230-8. 2006..For D-serine dehydratase, no structural data are available but nevertheless the metal ion arrangement in the PLP binding site can be predicted from 31P NMR data... - Tyrosine phenol-lyase and tryptophan indole-lyase encapsulated in wet nanoporous silica gels: Selective stabilization of tertiary conformationsBarbara Pioselli
Department of Biochemistry and Molecular Biology, University of Parma, Via Parco delle Scienze 23 A, 43100 Parma, Italy
Protein Sci 13:913-24. 2004..This finding indicates that subtle structural and dynamic differences can lead to distinct interactions of the protein with the gel matrix... - The second enzyme in pyrrolnitrin biosynthetic pathway is related to the heme-dependent dioxygenase superfamilyWalter De Laurentis
Centre for Biomolecular Sciences, EaStCHEM, The University, St Andrews, Scotland, KY16 9ST, UK
Biochemistry 46:12393-404. 2007.... - A Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetoneKarla I Ziegelmann Fjeld
Department of Biochemistry and Molecular Biology, Michigan State University, 410 Biochemistry Building, East Lansing, MI 48824 1319, USA
Protein Eng Des Sel 20:47-55. 2007..Our results suggest that (S)-2-butanol's orientation in the TbSADH*(S)-2-butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex... - Tryptophanase from Proteus vulgaris: the conformational rearrangement in the active site, induced by the mutation of Tyrosine 72 to phenylalanine, and its mechanistic consequencesVitalia V Kulikova
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov Street, Moscow 119991, Russia
Biochim Biophys Acta 1764:750-7. 2006.... - Protein expression in Escherichia coli S17-1 biofilms: impact of indoleAnthony Collet
IBBR Group, UMR 6522 CNRS, University of Rouen, 76821, Mont Saint Aignan, France
Antonie Van Leeuwenhoek 91:71-85. 2007..The role of some proteins whose expression was altered in biofilm bacteria compared to suspended counterparts is discussed... - The mechanism of alpha-proton isotope exchange in amino acids catalysed by tyrosine phenol-lyase. What is the role of quinonoid intermediates?Nicolai G Faleev
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
Eur J Biochem 271:4565-71. 2004..This result allows us to suggest the existence of an alternative, possibly concerted, mechanism of alpha-proton exchange... - Cold-induced enzyme inactivation: how does cooling lead to pyridoxal phosphate-aldimine bond cleavage in tryptophanase?Tali Erez
Department of Chemistry, Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
Biochim Biophys Acta 1594:335-40. 2002..It is proposed that cold inactivation is initiated by the weakening of hydrophobic interactions, leading to conformational changes which are the driving force for the aldimine bond cleavage... - A redox-active FKBP-type immunophilin functions in accumulation of the photosystem II supercomplex in Arabidopsis thalianaAmparo Lima
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
Proc Natl Acad Sci U S A 103:12631-6. 2006..The results provide evidence that FKBP20-2 participates specifically in the accumulation of the PSII supercomplex in the chloroplast thylakoid lumen by means of a mechanism that has yet to be determined...
Research Grants
- MECHANISMS OF CARBON-CARBON LYASES AND KYNURENINASERobert Phillips; Fiscal Year: 1993..Also, we will prepare mutants of tryptophan indole-lyase by sitedirected mutagenesis. These studies will allow us to evaluate the structural and catalytic roles of specific amino acid residues...
- MECHANISMS OF PYRIDOXAL-5'-PHOSPHATE DEPENDENT ENZYMESRobert Phillips; Fiscal Year: 2004..Thus the results of this research are likely to make a significant contribution to the goal of improving health care for Americans in the future. ..