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[PMID]: 26589585 [Au] Autor: Sharma B; Dabur R [Ad] Endereço: Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001, India. [Ti] Título: Protective Effects of Tinospora cordifolia on Hepatic and Gastrointestinal Toxicity Induced by Chronic and Moderate Alcoholism. [So] Source: Alcohol Alcohol;51(1):1-10, 2016 Jan. [Is] ISSN: 1464-3502 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: AIMS: Heavy alcohol intake depletes the plasma vitamins due to hepatotoxicity and decreased intestinal absorption. However, moderate alcohol intake is often thought to be healthy. Therefore, effects of chronic moderate alcohol intake on liver and intestine were studied using urinary vitamin levels. Furthermore, effects of Tinospora cordifolia water extract (TCE) (hepatoprotective) on vitamin excretion and intestinal absorption were also studied. METHODS: In the study, asymptomatic moderate alcoholics (n = 12) without chronic liver disease and healthy volunteers (n = 14) of mean age 39 ± 2.2 (mean ± SD) were selected and divided into three groups. TCE treatment was performed for 14 days. The blood and urine samples were collected on Day 0 and 14 after treatment with TCE and analyzed. RESULTS: In alcoholics samples, a significant increase in the levels of gamma-glutamyl transferase, aspartate transaminase, alanine transaminase, Triglyceride, Cholesterol, HDL and LDL (P < 0.05) was observed but their level get downregulated after TCE intervention. Multivariate analysis of metabolites without missing values showed an increased excretion of 7-dehydrocholesterol, orotic acid, pyridoxine, lipoamide and niacin and TCE intervention depleted their levels (P < 0.05). In contrast, excretion of biotin, xanthine, vitamin D2 and 2-O-p-coumaroyltartronic acid (CA, an internal marker of intestinal absorption) were observed to be decreased in alcoholic samples; however, TCE intervention restored the CA and biotin levels. Vitamin metabolism biomarkers, i.e. homocysteine and xanthurenic acid, were also normalized after TCE intervention. CONCLUSION: Overall data depict that moderate alcohol intake is also hepatotoxic and decreases intestinal absorption. However, TCE treatment effectively increased the intestinal absorption and retaining power of liver that regulated alcohol-induced multivitamin deficiency. [Mh] Termos MeSH primário: Alcoolismo/metabolismo Trato Gastrointestinal/efeitos dos fármacos Absorção Intestinal/efeitos dos fármacos Fígado/efeitos dos fármacos Extratos Vegetais/farmacologia Tinospora Vitaminas/metabolismo [Mh] Termos MeSH secundário: Adulto Biotina/metabolismo Estudos de Casos e Controles Ergocalciferóis/metabolismo Trato Gastrointestinal/metabolismo Homocisteína/metabolismo Seres Humanos Fígado/metabolismo Índice de Gravidade de Doença Tartronatos/metabolismo Vitaminas/sangue Vitaminas/urina Xantina/metabolismo Xanturenatos/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Ergocalciferols); 0 (Plant Extracts); 0 (Tartronates); 0 (Vitamins); 0 (Xanthurenates); 0LVT1QZ0BA (Homocysteine); 1AVZ07U9S7 (Xanthine); 34T0025E0L (tartronic acid); 58LAB1BG8J (xanthurenic acid); 6SO6U10H04 (Biotin) [Em] Mês de entrada: 1609 [Cu] Atualização por classe: 161126 [Lr] Data última revisão: 161126 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151122 [St] Status: MEDLINE [do] DOI: 10.1093/alcalc/agv130

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[PMID]: 25340352 [Au] Autor: Park H; Kevany BM; Dyer DH; Thomas MG; Forest KT [Ad] Endereço: Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America. [Ti] Título: A polyketide synthase acyltransferase domain structure suggests a recognition mechanism for its hydroxymalonyl-acyl carrier protein substrate. [So] Source: PLoS One;9(10):e110965, 2014. [Is] ISSN: 1932-6203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: We have previously shown that the acyl transferase domain of ZmaA (ZmaA-AT) is involved in the biosynthesis of the aminopolyol polyketide/nonribosomal peptide hybrid molecule zwittermicin A from cereus UW85, and that it specifically recognizes the precursor hydroxymalonyl-acyl carrier protein (ACP) and transfers the hydroxymalonyl extender unit to a downstream second ACP via a transacylated AT domain intermediate. We now present the X-ray crystal structure of ZmaA-AT at a resolution of 1.7 Å. The structure shows a patch of solvent-exposed hydrophobic residues in the area where the AT is proposed to interact with the precursor ACP. We addressed the significance of the AT/ACP interaction in precursor specificity of the AT by testing whether malonyl- or methylmalonyl-ACP can be recognized by ZmaA-AT. We found that the ACP itself biases extender unit selection. Until now, structural information for ATs has been limited to ATs specific for the CoA-linked precursors malonyl-CoA and (2S)-methylmalonyl-CoA. This work contributes to polyketide synthase engineering efforts by expanding our knowledge of AT/substrate interactions with the structure of an AT domain that recognizes an ACP-linked substrate, the rare hydroxymalonate. Our structure suggests a model in which ACP interaction with a hydrophobic motif promotes secondary structure formation at the binding site, and opening of the adjacent substrate pocket lid to allow extender unit binding in the AT active site. [Mh] Termos MeSH primário: Proteína de Transporte de Acila/química Aciltransferases/química Bacillus cereus/enzimologia Proteínas de Bactérias/química Tartronatos/química [Mh] Termos MeSH secundário: Motivos de Aminoácidos Domínio Catalítico Clonagem Molecular Cristalografia por Raios X Complexos Multienzimáticos/química Peptídeos Policetídeo Sintases/química Engenharia de Proteínas Estrutura Terciária de Proteína Especificidade por Substrato [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S. [Nm] Nome de substância: 0 (Acyl Carrier Protein); 0 (Bacterial Proteins); 0 (Multienzyme Complexes); 0 (Peptides); 0 (Tartronates); 155547-95-8 (zwittermicin A); 79956-01-7 (Polyketide Synthases); EC 2.3.- (Acyltransferases) [Em] Mês de entrada: 1602 [Cu] Atualização por classe: 170220 [Lr] Data última revisão: 170220 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 141024 [St] Status: MEDLINE [do] DOI: 10.1371/journal.pone.0110965

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[PMID]: 25307885 [Au] Autor: Breininger E; Vecchi Galenda BE; Alvarez GM; Gutnisky C; Cetica PD [Ad] Endereço: Area of Biochemistry, Institute of Research and Technology in Animal Production (INITRA), School of Veterinary Sciences, University of Buenos Aires, Buenos Aires, Argentina; Institute of Researches in Animal Production (INPA), UBA-CONICET (National Scientific and Technical Research Council), Buenos Aires, Argentina. [Ti] Título: Phosphofructokinase and malate dehydrogenase participate in the in vitro maturation of porcine oocytes. [So] Source: Reprod Domest Anim;49(6):1068-73, 2014 Dec. [Is] ISSN: 1439-0531 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Oocyte maturation depends on the metabolic activity of cumulus-oocyte complex (COC) that performs nutritive and regulatory functions during this process. In this work, the enzymes [phosphofructokinase (PFK) and malate dehydrogenase (MDH)] were tested to elucidate the metabolic profile of porcine COCs during the in vitro maturation (IVM). Enzymatic activity was expressed in U/COC and U/mg protein (specific activity) as mean ± SEM. In vitro maturation was performed with 2-oxoglutarate (5, 10 and 20 mm) or hydroxymalonate (30, 60 and 100 mm) inhibitors of PFK and MDH, respectively. The PFK and MDH activities (U) remained constant during maturation. For PFK, the U were (2.48 ± 0.23) 10(-5) and (2.54 ± 0.32) 10(-5) , and for MDH, the U were (4.72 ± 0.42) 10(-5) and (4.38 ± 0.25) 10(-5) for immature and in vitro matured COCs, respectively. The specific activities were significantly lower after IVM, for PFK (4.29 ± 0.48) 10(-3) and (0.94 ± 0.12) 10(-3) , and for MDH (9.08 ± 0.93) 10(-3) and (1.89 ± 0.10) 10(-3) for immature and in vitro matured COCs, respectively. In vitro maturation percentages and enzymatic activity diminished with 20 mm 2-oxoglutarate or 60 mm hydroxymalonate (p < 0.05). Viability was not affected by any concentration of the inhibitors evaluated. The U remained unchanged during IVM; however, the increase in the total protein content per COC provoked a decrease in the specific activity of both enzymes. Phosphofructokinase and MDH necessary for oocyte IVM would be already present in the immature oocyte. The presence of inhibitors of these enzymes impairs the meiotic maturation. Therefore, the participation of these enzymes in the energy metabolism of the porcine oocyte during IVM is confirmed in this study. [Mh] Termos MeSH primário: Técnicas de Maturação in Vitro de Oócitos/veterinária Malato Desidrogenase/metabolismo Oócitos/enzimologia Fosfofrutoquinases/metabolismo Suínos/fisiologia [Mh] Termos MeSH secundário: Animais Sobrevivência Celular Células do Cúmulo Regulação Enzimológica da Expressão Gênica/fisiologia Ácidos Cetoglutáricos/farmacologia Malato Desidrogenase/antagonistas & inibidores Malato Desidrogenase/genética Meiose/fisiologia Fosfofrutoquinases/antagonistas & inibidores Fosfofrutoquinases/genética Tartronatos/farmacologia [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Ketoglutaric Acids); 0 (Tartronates); 34T0025E0L (tartronic acid); EC 1.1.1.37 (Malate Dehydrogenase); EC 2.7.1 - (Phosphofructokinases) [Em] Mês de entrada: 1508 [Cu] Atualização por classe: 161125 [Lr] Data última revisão: 161125 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 141014 [St] Status: MEDLINE [do] DOI: 10.1111/rda.12437

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[PMID]: 24370400 [Au] Autor: Borer P; Hug SJ [Ad] Endereço: Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland. Electronic address: paul.borer@eawag.ch. [Ti] Título: Photo-redox reactions of dicarboxylates and α-hydroxydicarboxylates at the surface of Fe(III)(hydr)oxides followed with in situ ATR-FTIR spectroscopy. [So] Source: J Colloid Interface Sci;416:44-53, 2014 Feb 15. [Is] ISSN: 1095-7103 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Colloidal mineral-phases play an important role in the adsorption, transport and transformation of organic and inorganic compounds in the atmosphere and in aqueous environments. Artificial UV-light and sunlight can induce electron transfer reactions between metal ions of the solid phases and adsorbed compounds, leading to their transformation and degradation. To investigate different possible photo-induced oxidation pathways of dicarboxylates adsorbed on iron(III)(hydr)oxide surfaces, we followed UV-A induced photoreactions of oxalate, malonate, succinate and their corresponding α-hydroxy analogues tartronate and malate with in situ ATR-FTIR spectroscopy in immersed particle layers of lepidocrocite, goethite, maghemite and hematite at pH 4. UV-A light (365 ± 5 nm) lead to fast degradation of oxalate, tartronate and malate, while malonate and succinate were photo-degraded at much slower rates. Efficient generation of OH-radicals can be excluded, as this would lead to fast and indiscriminate degradation of all tested compounds. Rapid photo-degradation of adsorbed oxalate and the α-hydroxydicarboxylates must be induced by direct ligand-to-metal charge transfer (LMCT) or by selectively oxidizing valence band holes, both processes requiring inner-sphere coordination with direct ligand-to-metal bonds to enable efficient electron-transfer. The slow photo-degradation of malonate and succinate can be explained by low-yield production of OH-radicals at the surface of the iron(III)(hydr)oxides. [Mh] Termos MeSH primário: Malatos/química Malonatos/química Ácido Oxálico/química Ácido Succínico/química Tartronatos/química [Mh] Termos MeSH secundário: Adsorção Compostos Férricos/química Compostos de Ferro/química Cinética Minerais/química Oxirredução Fotólise Espectroscopia de Infravermelho com Transformada de Fourier/métodos Raios Ultravioleta [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Ferric Compounds); 0 (Iron Compounds); 0 (Malates); 0 (Malonates); 0 (Minerals); 0 (Tartronates); 1310-14-1 (goethite); 1K09F3G675 (ferric oxide); 34T0025E0L (tartronic acid); 817L1N4CKP (malic acid); 9E7R5L6H31 (Oxalic Acid); 9KX7ZMG0MK (malonic acid); AB6MNQ6J6L (Succinic Acid) [Em] Mês de entrada: 1407 [Cu] Atualização por classe: 161125 [Lr] Data última revisão: 161125 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 131228 [St] Status: MEDLINE

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[PMID]: 22437160 [Au] Autor: Qin J; Chai G; Brewer JM; Lovelace LL; Lebioda L [Ad] Endereço: Department of Chemistry & Biochemistry, University of South Carolina, Columbia, SC 29208, United States. [Ti] Título: Structures of asymmetric complexes of human neuron specific enolase with resolved substrate and product and an analogous complex with two inhibitors indicate subunit interaction and inhibitor cooperativity. [So] Source: J Inorg Biochem;111:187-94, 2012 Jun. [Is] ISSN: 1873-3344 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: In the presence of magnesium, enolase catalyzes the dehydration of 2-phospho-d-glycerate (PGA) to phosphoenolpyruvate (PEP) in glycolysis and the reverse reaction in gluconeogensis at comparable rates. The structure of human neuron specific enolase (hNSE) crystals soaked in PGA showed that the enzyme is active in the crystals and produced PEP; conversely soaking in PEP produced PGA. Moreover, the hNSE dimer contains PGA bound in one subunit and PEP or a mixture of PEP and PGA in the other. Crystals soaked in a mixture of competitive inhibitors tartronate semialdehyde phosphate (TSP) and lactic acid phosphate (LAP) showed asymmetry with TSP binding in the same site as PGA and LAP in the PEP site. Kinetic studies showed that the inhibition of NSE by mixtures of TSP and LAP is stronger than predicted for independently acting inhibitors. This indicates that in some cases inhibition of homodimeric enzymes by mixtures of inhibitors ("heteroinhibition") may offer advantages over single inhibitors. [Mh] Termos MeSH primário: Fosfopiruvato Hidratase/química Fosfopiruvato Hidratase/metabolismo Multimerização Proteica Estrutura Quaternária de Proteína [Mh] Termos MeSH secundário: Ligação Competitiva Cristalografia por Raios X Inibidores Enzimáticos/química Inibidores Enzimáticos/metabolismo Inibidores Enzimáticos/farmacologia Ácidos Glicéricos/química Ácidos Glicéricos/metabolismo Seres Humanos Cinética Modelos Moleculares Estrutura Molecular Fosfoenolpiruvato/química Fosfoenolpiruvato/metabolismo Fosfopiruvato Hidratase/genética Ligação Proteica Estrutura Terciária de Proteína Subunidades Proteicas/química Subunidades Proteicas/metabolismo Proteínas Recombinantes/antagonistas & inibidores Proteínas Recombinantes/química Proteínas Recombinantes/metabolismo Especificidade por Substrato Tartronatos/química Tartronatos/metabolismo Tartronatos/farmacologia [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Enzyme Inhibitors); 0 (Glyceric Acids); 0 (Protein Subunits); 0 (Recombinant Proteins); 0 (Tartronates); 118455-76-8 (tartronate semialdehyde phosphate); 2553-59-5 (2-phosphoglycerate); 73-89-2 (Phosphoenolpyruvate); EC 4.2.1.11 (Phosphopyruvate Hydratase) [Em] Mês de entrada: 1210 [Cu] Atualização por classe: 170220 [Lr] Data última revisão: 170220 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 120323 [St] Status: MEDLINE [do] DOI: 10.1016/j.jinorgbio.2012.02.011

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[PMID]: 20699632 [Au] Autor: Fiume L; Manerba M; Vettraino M; Di Stefano G [Ad] Endereço: Department of Experimental Pathology, University of Bologna, Italy. [Ti] Título: Impairment of aerobic glycolysis by inhibitors of lactic dehydrogenase hinders the growth of human hepatocellular carcinoma cell lines. [So] Source: Pharmacology;86(3):157-62, 2010. [Is] ISSN: 1423-0313 [Cp] País de publicação: Switzerland [La] Idioma: eng [Ab] Resumo: BACKGROUND/AIMS: by reducing the number of ATP molecules produced via aerobic glycolysis, the inhibition of lactic dehydrogenase (LDH) should hinder the growth of neoplastic cells without damaging the normal cells which do not rely on this metabolic pathway for their energetic needs. Here, we studied the effect of oxamic and tartronic acids, 2 inhibitors of LDH, on aerobic glycolysis and cell replication of HepG2 and PLC/PRF/5 cells, 2 lines from human hepatocellular carcinomas. METHODS: aerobic glycolysis was measured by calculating the amounts of lactic acid formed. The effect on replication was assessed by culturing the cells in both standard conditions and glucose-deprived medium, which was used to shut down aerobic glycolysis. RESULTS: the oxamic and tartronic acids inhibited aerobic glycolysis, impaired the growth of both cell lines and also induced an increased expression of p53-upregulated modulator of apoptosis, a signal of cell death. A strong impairment of cell replication by oxamic acid was only found when the cells were cultured in the presence of glucose, indicating that it was for the most part owing to inhibition of aerobic glycolysis. CONCLUSIONS: inhibition of aerobic glycolysis achieved by blocking LDH could be useful in the treatment of human hepatocellular carcinomas. Without interfering with glucose metabolism in normal cells, it could hinder cell growth by itself and could also enhance the chemotherapeutic index of associated anticancer agents by decreasing the levels of ATP selectively in neoplastic cells. [Mh] Termos MeSH primário: Carcinoma Hepatocelular/metabolismo Carcinoma Hepatocelular/patologia Glicólise/efeitos dos fármacos L-Lactato Desidrogenase/antagonistas & inibidores Ácido Láctico/metabolismo Ácido Oxâmico/farmacologia Tartronatos/farmacologia [Mh] Termos MeSH secundário: Trifosfato de Adenosina/metabolismo Antineoplásicos/farmacologia Antineoplásicos/uso terapêutico Apoptose/efeitos dos fármacos Proteínas Reguladoras de Apoptose/metabolismo Carcinoma Hepatocelular/tratamento farmacológico Linhagem Celular Tumoral Proliferação Celular/efeitos dos fármacos Ciclo do Ácido Cítrico Inibidores Enzimáticos/farmacologia Glucose/metabolismo Células Hep G2 Seres Humanos Consumo de Oxigênio/efeitos dos fármacos Proteínas Proto-Oncogênicas/metabolismo Regulação para Cima/efeitos dos fármacos [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Antineoplastic Agents); 0 (Apoptosis Regulatory Proteins); 0 (BBC3 protein, human); 0 (Enzyme Inhibitors); 0 (Proto-Oncogene Proteins); 0 (Tartronates); 33X04XA5AT (Lactic Acid); 34T0025E0L (tartronic acid); 8L70Q75FXE (Adenosine Triphosphate); EC 1.1.1.27 (L-Lactate Dehydrogenase); IY9XDZ35W2 (Glucose); QU60N5OPLG (Oxamic Acid) [Em] Mês de entrada: 1102 [Cu] Atualização por classe: 161125 [Lr] Data última revisão: 161125 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 100812 [St] Status: MEDLINE [do] DOI: 10.1159/000317519

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[PMID]: 20353188 [Au] Autor: Chan YA; Thomas MG [Ad] Endereço: Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, Wisconsin 53706, USA. [Ti] Título: Recognition of (2S)-aminomalonyl-acyl carrier protein (ACP) and (2R)-hydroxymalonyl-ACP by acyltransferases in zwittermicin A biosynthesis. [So] Source: Biochemistry;49(17):3667-77, 2010 May 04. [Is] ISSN: 1520-4995 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Polyketide synthases elongate a polyketide backbone by condensing carboxylic acid precursors that are thioesterified to either coenzyme A or an acyl carrier protein (ACP). Two of the three known ACP-linked extender units, (2S)-aminomalonyl-ACP and (2R)-hydroxymalonyl-ACP, are found in the biosynthesis of the agriculturally important antibiotic zwittermicin A. We previously reconstituted the formation of (2S)-aminomalonyl-ACP and (2R)-hydroxymalonyl-ACP from the primary metabolites l-serine and 1,3-bisphospho-d-glycerate. In this report, we characterize the two acyltransferases involved in the specific transfer of the (2S)-aminomalonyl and (2R)-hydroxymalonyl moieties from the ACPs associated with extender unit formation to the ACPs integrated into the polyketide synthase. This work establishes which acyltransferase recognizes each extender unit and also provides insight into the substrate selectivity of these enzymes. These are important step toward harnessing these rare polyketide synthase extender units for combinatorial biosynthesis. [Mh] Termos MeSH primário: Proteína de Transporte de Acila/metabolismo Aciltransferases/metabolismo Malonatos/metabolismo Peptídeos/metabolismo Tartronatos/metabolismo [Mh] Termos MeSH secundário: Proteína de Transporte de Acila/química Proteína de Transporte de Acila/isolamento & purificação Cromatografia Líquida de Alta Pressão Plasmídeos Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz Estereoisomerismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL [Nm] Nome de substância: 0 (Acyl Carrier Protein); 0 (Malonates); 0 (Peptides); 0 (Tartronates); 1068-84-4 (aminomalonic acid); 155547-95-8 (zwittermicin A); 34T0025E0L (tartronic acid); EC 2.3.- (Acyltransferases) [Em] Mês de entrada: 1005 [Cu] Atualização por classe: 161125 [Lr] Data última revisão: 161125 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 100401 [St] Status: MEDLINE [do] DOI: 10.1021/bi100141n

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[PMID]: 20102712 [Au] Autor: Brewer JM; McKinnon JS; Phillips RS [Ad] Endereço: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, United States. brewer@bmb.uga.edu [Ti] Título: Stopped-flow studies of the reaction of D-tartronate semialdehyde-2-phosphate with human neuronal enolase and yeast enolase 1. [So] Source: FEBS Lett;584(5):979-83, 2010 Mar 05. [Is] ISSN: 1873-3468 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: We determined the kinetics of the reaction of human neuronal enolase and yeast enolase 1 with the slowly-reacting chromophoric substrate D-tartronate semialdehyde phosphate (TSP), each in tris (tris (hydroxymethyl) aminomethane) and another buffer at several Mg2+ concentrations, 50 or 100 microM, 1 mM and 30 mM. All data were biphasic, and could be satisfactorily fit, assuming either two successive first-order reactions or two independent first-order reactions. 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. [Mh] Termos MeSH primário: Fosfopiruvato Hidratase/metabolismo Proteínas de Saccharomyces cerevisiae/metabolismo Tartronatos/metabolismo [Mh] Termos MeSH secundário: Seres Humanos Cinética Magnésio/metabolismo Ligação Proteica Especificidade por Substrato [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Saccharomyces cerevisiae Proteins); 0 (Tartronates); 118455-76-8 (tartronate semialdehyde phosphate); EC 4.2.1.11 (ENO1 protein, S cerevisiae); EC 4.2.1.11 (Phosphopyruvate Hydratase); I38ZP9992A (Magnesium) [Em] Mês de entrada: 1003 [Cu] Atualização por classe: 131121 [Lr] Data última revisão: 131121 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 100128 [St] Status: MEDLINE [do] DOI: 10.1016/j.febslet.2010.01.042

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[PMID]: 19101968 [Au] Autor: Reddy DS; Shibata N; Nagai J; Nakamura S; Toru T [Ad] Endereço: Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan. [Ti] Título: A dynamic kinetic asymmetric transformation in the alpha-hydroxylation of racemic malonates and its application to biologically active molecules. [So] Source: Angew Chem Int Ed Engl;48(4):803-6, 2009. [Is] ISSN: 1521-3773 [Cp] País de publicação: Germany [La] Idioma: eng [Mh] Termos MeSH primário: Malonatos/química Tartronatos/química [Mh] Termos MeSH secundário: Antagonistas de Androgênios/síntese química Anilidas/síntese química Antineoplásicos/síntese química Hidroxilação Cinética Nitrilos/síntese química Estereoisomerismo Compostos de Tosil/síntese química [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Androgen Antagonists); 0 (Anilides); 0 (Antineoplastic Agents); 0 (Malonates); 0 (Nitriles); 0 (Tartronates); 0 (Tosyl Compounds); 34T0025E0L (tartronic acid); A0Z3NAU9DP (bicalutamide) [Em] Mês de entrada: 0901 [Cu] Atualização por classe: 161124 [Lr] Data última revisão: 161124 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 081223 [St] Status: MEDLINE [do] DOI: 10.1002/anie.200804476

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[PMID]: 13678299 [Au] Autor: Brewer JM; Glover CV; Holland MJ; Lebioda L [Ad] Endereço: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA. brewer@bmb.uga.edu [Ti] Título: Enzymatic function of loop movement in enolase: preparation and some properties of H159N, H159A, H159F, and N207A enolases. [So] Source: J Protein Chem;22(4):353-61, 2003 May. [Is] ISSN: 0277-8033 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The hypothesis that His159 in yeast enolase moves on a polypeptide loop to protonate the phosphoryl of 2-phosphoglycerate to initiate its conversion to phosphoenolpyruvate was tested by preparing H159N, H159A, and H159F enolases. These have 0.07%-0.25% of the native activity under standard assay conditions and the pH dependence of maximum velocities of H159A and H159N mutants is markedly altered. Activation by Mg2+ is biphasic, with the smaller Mg2+ activation constant closer to that of the "catalytic" Mg2+ binding site of native enolase and the larger in the mM range in which native enolase is inhibited. A third Mg2+ may bind to the phosphoryl, functionally replacing proton donation by His159. N207A enolase lacks an intersubunit interaction that stabilizes the closed loop(s) conformation when 2-phosphoglycerate binds. It has 21% of the native activity, also exhibits biphasic Mg2+ activation, and its reaction with the aldehyde analogue of the substrate is more strongly inhibited than is its normal enzymatic reaction. Polypeptide loop(s) closure may keep a proton from His159 interacting with the substrate phosphoryl oxygen long enough to stabilize a carbanion intermediate. [Mh] Termos MeSH primário: Fosfopiruvato Hidratase/química Fosfopiruvato Hidratase/metabolismo Saccharomyces cerevisiae/enzimologia [Mh] Termos MeSH secundário: Animais Varredura Diferencial de Calorimetria Relação Dose-Resposta a Droga Ativação Enzimática/efeitos dos fármacos Histidina/genética Histidina/metabolismo Concentração de Íons de Hidrogênio Magnésio/farmacologia Mutagênese Sítio-Dirigida/genética Mutação/genética Fosfopiruvato Hidratase/genética Estrutura Quaternária de Proteína/efeitos dos fármacos Subunidades Proteicas/química Subunidades Proteicas/metabolismo Saccharomyces cerevisiae/genética Tartronatos/farmacologia Temperatura Ambiente [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Protein Subunits); 0 (Tartronates); 118455-76-8 (tartronate semialdehyde phosphate); 4QD397987E (Histidine); EC 4.2.1.11 (Phosphopyruvate Hydratase); I38ZP9992A (Magnesium) [Em] Mês de entrada: 0404 [Cu] Atualização por classe: 131121 [Lr] Data última revisão: 131121 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 030919 [St] Status: MEDLINE

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