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385 results on '"Herzberg, Osnat"'

51. Inactivation of microbial arginine deiminases by L-canavanine

Author

Ling Li, Zhimin Li, Danqi Chen, Xuefeng Lu, Xiaohua Feng, Wright, Elizabeth C., Solberg, Nathan O., Dunaway-Mariano, Debra, Mariano, Patrick S., Galkin, Andrey, Kulakova, Liudmila, Herzberg, Osnat, Green-Church, Kari B., and Liwen Zhang

Subjects
Arginine -- Chemical properties, Catalysis -- Research, Hydrolysis -- Research, Pseudomonas aeruginosa -- Physiological aspects, Chemistry
Abstract

The isolation, structure and chemical mechanism for catalysis of the Pseudomonas aeruginosa, arginine deiminase (ADI) (L-arginine) which involves initial formation and subsequent hydrolysis of a Cys-alkylthiouronium ion intermediate is described. The findings from the studies would help to design the arginine analogs such as L-canavanine that migaht react with the ADIs to form inactive covalent adduct during catalytic turnover.

Published
2008

52. Structure and function of PA4872 from Pseudomonas aeruginosa, a novel class of oxaloacetate decarboxylase from the PEP mutase/isocitrate lyase superfamily

Author

Narayanan, Buvaneswari C., Weiling Niu, Jiwen Zou, Ying Han, Mariano, Patrick S., Dunaway-Mariano, Debra, and Herzberg, Osnat

Subjects
Decarboxylases -- Chemical properties, Nuclear magnetic resonance spectroscopy -- Technology application, Oxalates -- Chemical properties, Pseudomonas aeruginosa -- Physiological aspects, Pyruvates -- Research, Technology application, Biological sciences, Chemistry
Abstract

The crystal structure of PA4872 from Pseudomonas aeruginosa in complex with oxalate and [Mg.sup.2+] is studied. The results have shown that PA4872 is an oxaloacetate decarboxylase, which is used primarily by pseudomonas, and that the enzyme is used by differential bacterial species to maintain pyruvate and bicarbonate cellular levels in many pathways.

Published
2008

53. Structure and kinetics of phosphonopyruvate hydrolase from voriovorax sp. Pal2: New insight into the divergence of catalysis within the PEP mutase/isocitrate lyase superfamily

Author

Celia C.H. Chen, Ying Han, Weiling Niu, Kulakova, Anna N., Howard, Andrew, Quinn, John P., Dunaway-Mariano, Debra, and Herzberg, Osnat

Subjects
Hydrolases -- Analysis, Enzymes -- Analysis, Escherichia coli -- Research, Biological sciences, Chemistry
Abstract

The structure and properties of recombinant phosphonopyruvate (P-pyr) hydrolase (PPH) from variovorax sp. Pal2 expressed in E. coli is reported. Structure alignment of PPH with other superfamily members revealed two pairs of invariant or conservatively replaced residues that anchor the flexible gating loop.

Published
2006

54. Mechanisms of catalysis and inhibition operative in the arginine deiminase from the human pathogen Giardia lamblia

Author

Li, Zhimin, Kulakova, Liudmila, Li, Ling, Galkin, Andrey, Zhao, Zhiming, Knipp, Markus, Nash, Theodore E., Mariano, Patrick S., Herzberg, Osnat, and Dunaway-Mariano, Debra

Subjects
Models, Molecular, Tris, Hydrolases, Stereochemistry, medicine.disease_cause, Biochemistry, Article, chemistry.chemical_compound, Drug Discovery, Hydrolase, Escherichia coli, medicine, Animals, Giardia lamblia, Gene Silencing, Molecular Biology, Arginine deiminase, chemistry.chemical_classification, biology, Organic Chemistry, Active site, Kinetics, Enzyme, chemistry, Biocatalysis, biology.protein, Electrophoresis, Polyacrylamide Gel, Agmatine
Abstract

Giardia lamblia arginine deiminase (GlAD), the topic of this paper, belongs to the hydrolase branch of the guanidine-modifying enzyme superfamily, whose members employ Cys-mediated nucleophilic catalysis to promote deimination of l-arginine and its naturally occurring derivatives. G. lamblia is the causative agent in the human disease giardiasis. The results of RNAi/antisense RNA gene-silencing studies reported herein indicate that GlAD is essential for G. lamblia trophozoite survival and thus, a potential target for the development of therapeutic agents for the treatment of giardiasis. The homodimeric recombinant protein was prepared in Escherichia coli for in-depth biochemical characterization. The 2-domain GlAD monomer consists of a N-terminal domain that shares an active site structure (depicted by an insilico model) and kinetic properties (determined by steady-state and transient state kinetic analysis) with its bacterial AD counterparts, and a C-terminal domain of unknown fold and function. GlAD was found to be active over a wide pH range and to accept l-arginine, l-arginine ethyl ester, N(alpha)-benzoyl-l-arginine, and N(omega)-amino-l-arginine as substrates but not agmatine, l-homoarginine, N(alpha)-benzoyl-l-arginine ethyl ester or a variety of arginine-containing peptides. The intermediacy of a Cys424-alkylthiouronium ion covalent enzyme adduct was demonstrated and the rate constants for formation (k(1)=80s(-1)) and hydrolysis (k(2)=35s(-1)) of the intermediate were determined. The comparatively lower value of the steady-state rate constant (k(cat)=2.6s(-1)), suggests that a step following citrulline formation is rate-limiting. Inhibition of GlAD using Cys directed agents was briefly explored. S-Nitroso-l-homocysteine was shown to be an active site directed, irreversible inhibitor whereas N(omega)-cyano-l-arginine did not inhibit GlAD but instead proved to be an active site directed, irreversible inhibitor of the Bacillus cereus AD.

Published
2009

55. Crystal structures of 2-methylisocitrate lyase in complex with product and with isocitrate inhibitor provide insight into lyase substrate specificity, catalysis and evolution

Author

Sijjiu Liu, Yin Han, Zhibing Lu, Melamud, Eugene, Dunaway-Mariano, and Herzberg, Osnat

Subjects
Methyl groups -- Chemical properties, Catalysis -- Research, Lyases -- Chemical properties, Crystals -- Structure, Crystals -- Research, Biological sciences, Chemistry
Abstract

The two crystal structures of the C123S mutant of 2-methylisocitrate lyase have been determined, one with the bound reaction products. The structure-based sequence analysis and phylogenic tree construction reveal determinants of substrate specificity, highlight nodes of divergence of families, and predict enzyme families with new functions.

Published
2005

57. Arginine deiminase uses an active-site cysteine in nucleophilic catalysis of L-arginine hydrolysis

Author

Lu, Xuefeng, Galkin, Andrey, Herzberg, Osnat, and Dunaway-Mariano, Debra

Subjects
Arginine -- Properties, Catalysis -- Research, Chemistry
Abstract

The results from transient-state kinetic experiments which show that arginine deiminase catalysis proceeds through a covalent adduct formed by activesite Cys406 displacement of ammonia from the guanidium carbon of L-arginine are presented.

Published
2004

58. Conformational flexibility of PEP mutase

Author

Liu, Sijiu, Han, Ying, Lu, Zhibing, Jia, Yong, Howard, Andrew, Dunaway-Mariano, Debra, and Herzberg, Osnat

Subjects
Biochemistry -- Research, Mutagenesis -- Research, Conformational analysis, Biological sciences, Chemistry
Abstract

The crystal structures of wild-type and D58A mutases, in the apo state and in complex with Mg(II), are presented. The members of the phosphoenolpyruvate (PEP) mutase/isocitratelyase (ICL) family share sequence homology and overall fold, and use similar modes of flexibility.

Published
2004

67. Challenging the state of the art in protein structure prediction: Highlights of experimental target structures for the 10th Critical Assessment of Techniques for Protein Structure Prediction Experiment CASP10

Author

Kryshtafovych, Andriy, primary, Moult, John, additional, Bales, Patrick, additional, Bazan, J. Fernando, additional, Biasini, Marco, additional, Burgin, Alex, additional, Chen, Chen, additional, Cochran, Frank V., additional, Craig, Timothy K., additional, Das, Rhiju, additional, Fass, Deborah, additional, Garcia-Doval, Carmela, additional, Herzberg, Osnat, additional, Lorimer, Donald, additional, Luecke, Hartmut, additional, Ma, Xiaolei, additional, Nelson, Daniel C., additional, van Raaij, Mark J., additional, Rohwer, Forest, additional, Segall, Anca, additional, Seguritan, Victor, additional, Zeth, Kornelius, additional, and Schwede, Torsten, additional

Published
2014
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68. Bacterial resistance to beta-lactam antibiotics: crystal structure of beta-lactamase from Staphylococcus aureus PC1 at 2.5 angstrom resolution

Author

Herzberg, Osnat and Moult, John

Subjects
Microbial enzymes -- Research -- Analysis, Beta lactamases -- Research -- Analysis, Molecular structure -- Analysis -- Research, Science and technology, Analysis, Research
Abstract

Bacterial Resistance to Β-Lactam Antibiotics: Crystal Structure of Β-Lactamase from Staphylococcus aureus PCI at 2.5 Å Resolution MANY TYPES OF DEFENSE MECHANISMS EXIST IN THEbiologigal world, and relatively lowly life [...]

Published
1987

85. Inactivation of Microbial Arginine Deiminases by l-Canavanine

Author

Li, Ling, primary, Li, Zhimin, additional, Chen, Danqi, additional, Lu, Xuefeng, additional, Feng, Xiaohua, additional, Wright, Elizabeth C., additional, Solberg, Nathan O., additional, Dunaway-Mariano, Debra, additional, Mariano, Patrick S., additional, Galkin, Andrey, additional, Kulakova, Liudmila, additional, Herzberg, Osnat, additional, Green-Church, Kari B., additional, and Zhang, Liwen, additional

Published
2008
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91. Kinetic Analysis of Pseudomonas aeruginosa Arginine Deiminase Mutants and Alternate Substrates Provides Insight into Structural Determinants of Function

Author

Lu, Xuefeng, primary, Li, Ling, additional, Wu, Rui, additional, Feng, Xiaohua, additional, Li, Zhimin, additional, Yang, Heyi, additional, Wang, Canhui, additional, Guo, Hua, additional, Galkin, Andrey, additional, Herzberg, Osnat, additional, Mariano, Patrick S., additional, Martin, Brian M., additional, and Dunaway-Mariano, Debra, additional

Published
2006
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92. Diversity of Function in the Isocitrate Lyase Enzyme Superfamily: The Dianthus caryophyllus Petal Death Protein Cleaves α-Keto and α-Hydroxycarboxylic Acids

Author

Lu, Zhibing, primary, Feng, Xiaohua, additional, Song, Ling, additional, Han, Ying, additional, Kim, Alexander, additional, Herzberg, Osnat, additional, Woodson, William R., additional, Martin, Brian M., additional, Mariano, Patrick S., additional, and Dunaway-Mariano, Debra, additional

Published
2005
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