Enzyme Catalysis
Mostrando 13-24 de 558 artigos, teses e dissertações.
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13. Purificação e caracterização de uma β-glucuronidase extraída do molusco mesogastropoda ampularidade Pomacea sp
This work studies the involved enzymatic way in the metabolism of glycosaminoglycans sulfateds in the mollusc Pomacea sp. Had been identified endoglycosidases and exoglycosidases in the enzymatic extract of the mollusc Pomacea sp by means of hydrolysis activity in condroitim sulphate of whale cartilage and of the p-Nitrofenil-β-glucuronide, respectively
Publicado em: 2006
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14. High-throughput screening in enzyme assays for epoxide hydrolases and monooxygenases activity detection using whole cell / Triagem de alto desempenho para detecção de atividade de epoxido-hidrolases e monooxigenases utilizando celulas integras
Biocatalysis is a multidisciplinary area, where new technologies are developing rapidly in order to offer unique options and solutions to different organic chemistry problems, complementing the classical synthetic chemistry. Facing the need imposed by progress in this area, this project aims at the implementation of high-throughput screening (HTS) methodolog
Publicado em: 2006
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15. Nonconventional amide bond formation catalysis: programming enzyme specificity with substrate mimetics
This article reports on the design and characteristics of substrate mimetics in protease-catalyzed reactions. Firstly, the basis of protease-catalyzed peptide synthesis and the general advantages of substrate mimetics over common acyl donor components are described. The binding behavior of these artificial substrates and the mechanism of catalysis are furthe
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-05
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16. Estudo da utilização de lipases no enriquecimento de oleos de sardinha e Mucor sp em acidos graxos poliinsaturados
The present work reports the study of the hydrolysis and etherification reactions catalyzed by microorganism lipases, which were isolated at the "Laboratorio de Bioquímica de Alimentos - FEA - UNICAMP", belonging to Rhizopus sp, Geotrichum sp, Aspergillus sp and the commerciallipase Candida cylindracea. The aim was the enrichment of polyunsaturated fatty ac
Publicado em: 1998
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17. Relation between enzymic catalysis and energy coupling.
The principles that underlie enzyme catalysis also apply to energy coupling processes. A comparison is made between a kinase system that mediates the phosphorylation of glucose by ATP (hexokinase), as the prototype for enzymic catalysis, and the mitochondrial electron-transfer complexes, as the prototypes for energy coupling systems. Induced polarization of
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18. On the mechanism of action of ribonucleases: dinucleotide cleavage catalyzed by imidazole and Zn2+.
Cyclization/cleavage of the 2-(p-nitrophenyl) phosphate ester of propylene glycol is catalyzed by imidazole and, much more effectively, by Zn2+ with imidazole. In the latter case, the mechanism involves simultaneous Lewis acid/base catalysis. Similar Zn2+ and imidazole catalysis of cyclization/cleavage is seen with the dinucleotide 3',5'-UpU (uridylyluridine
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19. Measuring Solution Viscosity and its Effect on Enzyme Activity
In proteins, some processes require conformational changes involving structural domain diffusion. Among these processes are protein folding, unfolding and enzyme catalysis. During catalysis some enzymes undergo large conformational changes as they progress through the catalytic cycle. According to Kramers theory, solvent viscosity results in friction against
Biological Procedures Online.
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20. Mutational Analysis of Bacillus subtilis Glutamine Phosphoribosylpyrophosphate Amidotransferase Propeptide Processing†
Glutamine phosphoribosylpyrophosphate amidotransferase from Bacillus subtilis is a member of an N-terminal nucleophile hydrolase enzyme superfamily, several of which undergo autocatalytic propeptide processing to generate the mature active enzyme. A series of mutations was analyzed to determine whether amino acid residues required for catalysis are also used
American Society for Microbiology.
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21. Energetics of enzyme catalysis.
Quantitative studies of the energetics of enzymatic reactions and the corresponding reactions in aqueous solutions indicate that charge stabilization is the most important energy contribution in enzyme catalysis. Low electrostatic stabilization in aqueous solutions is shown to be consistent with surprisingly large electrostatic stabilization effects in activ
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22. Pause and rotation of F1-ATPase during catalysis
F1-ATPase is a rotary motor enzyme in which a single ATP molecule drives a 120° rotation of the central γ subunit relative to the surrounding α3β3 ring. Here, we show that the rotation of F1-ATPase spontaneously lapses into long (≈30 s) pauses during steady-state catalysis. The effects of ADP-Mg and mutation on the pauses, as well as kinetic comparison
The National Academy of Sciences.
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23. Surveyor Substrates: Energy-Transfer Gauges of Active Center Topography during Catalysis*
An approach is described for the simultaneous measurement of catalysis, the distance from an active-site moiety to fluorescent substrate moieties of an enzyme substrate complex, and the microenvironment of such substrate groups. It is illustrated by means of a three-component energy transfer relay system, consisting of cobalt carboxypeptidase, its fluorescen
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24. CONFORMATIONAL CHANGES IN ENZYME CATALYSIS