Search results for "dehydrogenases"
showing 10 items of 55 documents
Temperature dependence of dynamic, tunnelling and kinetic isotope effects in formate dehydrogenase
2018
The origin of the catalytic power of enzymes has been a question of debate for a long time. In this regard, the possible contribution of protein dynamics in enzymatic catalysis has become one of the most controversial topics. In the present work, the hydride transfer step in the formate dehydrogenase (FDH EC 1.2.1.2) enzyme is studied by means of molecular dynamic (MD) simulations with quantum mechanics/molecular mechanics (QM/MM) potentials in order to explore any correlation between dynamics, tunnelling effects and the rate constant. The temperature dependence of the kinetic isotope effects (KIEs), which is one of the few tests that can be studied by experiments and simulations to shed li…
A critical role of plastidial glycolytic Glyceraldehyde-3-Phosphate Dehydrogenase in the control of plant metabolism and development
2009
3 páginas.
Interactions between abscisic acid and plastidial glycolysis in Arabidopsis
2011
[EN] The phytohormone abscisic acid (ABA) controls the development of plants and plays a crucial role in their response to adverse environmental conditions like salt and water stress.1-3 Complex interactions between ABA and sugar signal transduction pathways have been shown. However, the role played by glycolysis in these interactions is not known. In the associated study,4 we investigated the interactions between plastidial glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPCp) and ABA signal transduction in Arabidopsis. We followed physiological, genetic and genomic approaches to understand the processes and mechanisms underlying the ABAglycolysis interactions. Our results indicated …
Peroxisomal and mitochondrial status of two murine oligodendrocytic cell lines (158N, 158JP): potential models for the study of peroxisomal disorders…
2009
International audience; In some neurodegenerative disorders (leukodystrophies) characterized by myelin alterations, the defect of peroxisomal functions on myelin-producing cells (oligodendrocytes) are poorly understood. The development of in vitro models is fundamental to understanding the physiopathogenesis of these diseases. We characterized two immortalized murine oligodendrocyte cell lines: a normal (158N) and a jimpy (158JP) cell line mutated for the proteolipid protein PLP/DM20. Fluorescence microscopy, flow cytometry, and western blotting analysis allow to identify major myelin proteins (PLP colocalizing with mitochondria; myelin basic protein), oligodendrocyte (CNPase and myelin oli…
Purification of a biologically active recombinant glyceraldehyde 3-phosphate dehydrogenase fromCandida albicans
1999
We report here the purification of a functionally active recombinant glyceraldehyde 3-phosphate dehydrogenase (GAPDH) from Candida albicans. The GAPDH protein encoded by the TDH1 gene was obtained as a glutathione S-transferase fusion protein by expression in the vector pGEX-4T-3, and purified by affinity chromatography and thrombin digestion. The purified protein displays GAPDH enzymatic activity (42 micromol NADH min(-1) mg(-1)) as well as the laminin and fibronectin binding activities previously described. In addition, the recombinant GAPDH is covalently modified by NAD linkage; this modification is stimulated by nitric oxide and probably involves a sulfhydryl group (cysteine) residue si…
The formation of hybrid complexes between isoenzymes of glyceraldehyde‐3‐phosphate dehydrogenase regulates its aggregation state, the glycolytic acti…
2019
The glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) has been traditionally considered a housekeeping protein involved in energy generation. However, evidence indicates that GAPDHs from different origins are tightly regulated and that this regulation may be on the basis of glycolysis‐related and glycolysis‐unrelated functions. In Saccharomyces cerevisiae, Tdh3 is the main GAPDH, although two other isoenzymes encoded by TDH1 and TDH2 have been identified. Like other GAPDHs, Tdh3 exists predominantly as a tetramer, although dimeric and monomeric forms have also been isolated. Mechanisms of Tdh3 regulation may thus imply changes in its oligomeric state or be based in its abil…
Starvation and temperature upshift cause an increase in the enzymatically active cell wall-associated glyceraldehyde-3-phosphate dehydrogenase protei…
2003
The cell wall-associated glyceraldehyde-3-phosphate dehydrogenase (cwGAPDH) activity in Saccharomyces cerevisiae increases (two- to 10-fold, depending on the strain) in response to starvation and temperature upshift. Assays using transformants carrying pTDH, a yeast centromer derivative plasmid containing the Candida albicans TDH3 gene (encoding GAPDH) fused in frame with the yeast SUC2-coding region for internal invertase, showed that starvation and/or temperature upshift result in a similar increase in both cwGAPDH and cell wall-associated invertase activities. In addition, this incorporation of GAPDH protein into the cell wall in response to stress does not require (i) de novo protein sy…
Screening of Ovarian steroidogenic pathway in Ciona intestinalis and its modulation after Tributyltin exposure
2010
In this study, we have identified several ovarian steroids in Ciona with high similarity to vertebrate steroids and showed that cholesterol, corticosterone, dehydroepiandrosterone, estrone, estradiol-17beta, testosterone, pregnenolone, progesterone, have identical molecular spectra with vertebrate steroids. In addition, we have studied the effects of an endocrine disruptor (tributyltin: TBT) on these sex hormones and their precursors, ovarian morphology, and gene expression of some key enzymes in steroidogenic pathway in the ovary of Ciona. Ovarian specimens were cultured in vitro using different concentrations of TBT (10{sup -5}, 10{sup -4} and 10{sup -3} M). Ethanol was used as solvent co…
Do dynamic effects play a significant role in enzymatic catalysis? A theoretical analysis of formate dehydrogenase.
2010
A theoretical study of the protein dynamic effects on the hydride transfer between the formate anion and nicotinamide adenine dinucleotide (NAD + ), catalyzed by formate dehydrogenase (FDH), is presented in this paper. The analysis of free downhill molecular dynamic trajectories, performed in the enzyme and compared with the reaction in aqueous solution, has allowed the study of the dynamic coupling between the reacting fragments and the protein or the solvent water molecules, as well as an estimation of the dynamic effect contribution to the catalytic effect from calculation of the transmission coefficient in the enzyme and in solution. The obtained transmission coefficients for the enzyme…
Glyceraldehyde-3-phosphate dehydrogenase regulates endothelin-1 expression by a novel, redox-sensitive mechanism involving mRNA stability
2008
17 pages.-- PMID: 18809573 [PubMed].-- Printed version published on Dec 2008.