Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this report the disturbances in biochemistry of the heart muscle exposed to alcohol are delineated. All elements of cellular substructures are affected. In plasma membranes, (Na+ + K+)-activated ATPase (EC 3.6.1.3) is inhibited. Mitochondrial damage consists in diminished respiratory function and calcium uptake and binding. High-energy phosphates remain intact. Alcohol also affects the malate-aspartate shuttle. Acetaldehyde, a metabolite of ethanol, has a direct effect on myocardial protein synthesis through microsomal inhibition; however, the development of cardiac hypertrophy is not affected. Malfunction of sarcoplasmic reticulum is evidenced by disturbances in calcium binding and uptake. Effects of ethanol on the contractile machinery are deficiencies in the turnover rate of chemical into mechanical energy (diminished Vmax), and in the number of cross-bridges formed (P0). It increases stiffness of series elastic elements. There is diminished fatty acid oxidation with increased esterification. The involvement of CoA synthetase (EC 6.2.1.1), palmityl-carnitine transferase (EC 2.3.1.7), and pyruvate dehydrogenase complex in disturbed fatty acid oxidation is not certain. The role of catalase in myocardial ethanol oxidation was examined. Ethanol activates myocardial catalase-H2O2 complex (EC 1.11.1.6). The biochemical basis of fetal alcohol syndrome is low hepatic alcohol dehydrogenase (EC 1.1.1.1) activity during fetal life.
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PMID:Effect of alcohol on the heart and cardiac metabolism. 628 54

Acetaldehyde is one of the intermediate products of ethanolic fermentation, which can be reduced to ethanol by alcohol dehydrogenase (ADH). Alternatively, acetaldehyde can be oxidized to acetate by aldehyde dehydrogenase (ALDH) and subsequently converted to acetyl-CoA by acetyl-CoA synthetase (ACS). To study the expression of ALDHs in plants we isolated and characterized a cDNA coding for a putative mitochondrial ALDH (TobAldh2A) in Nicotiana tabacum. TobALDH2A shows 54-60% identity at the amino acid level with other ALDHs and shows 76% identity with maize Rf2, a gene involved in restoration of male fertility in cms-T maize. TobAldh2A transcripts and protein were present at high levels in the male and female reproductive tissues. Expression in vegetative tissues was much lower and no induction by anaerobic incubation was observed. This suggests that TobALDH expression is not part of the anaerobic response, but may have another function. The use of specific inhibitors of ALDH and the pyruvate dehydrogenase (PDH) complex indicates that ALDH activity is important for pollen tube growth, and thus may have a function in biosynthesis or energy production.
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PMID:Aldehyde dehydrogenase in tobacco pollen. 934 59

The role of ethylene in regulating sugar, acid, texture and volatile components of fruit quality was investigated in transgenic apple fruit modified in their capacity to synthesize endogenous ethylene. Fruit obtained from plants silenced for either ACS (ACC synthase; ACC-1-aminocyclopropane-1-carboxylic acid) or ACO (ACC oxidase), key enzymes responsible for ethylene biosynthesis, expectedly showed reduced autocatalytic ethylene production. Ethylene suppressed fruits were significantly firmer than controls and displayed an increased shelf-life. No significant difference was observed in sugar or acid accumulation suggesting that sugar and acid composition and accumulation is not directly under ethylene control. Interestingly, a significant and dramatic suppression of the synthesis of volatile esters was observed in fruit silenced for ethylene. However, no significant suppression was observed for the aldehyde and alcohol precursors of these esters. Our results indicate that ethylene differentially regulates fruit quality components and the availability of these transgenic apple trees provides a unique resource to define the role of ethylene and other factors that regulate fruit development.
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PMID:Effect of down-regulation of ethylene biosynthesis on fruit flavor complex in apple fruit. 1551 96

The roles of the enzyme which forms 5-hydroxy-4-ketohexanoate (HKH) and of related enzymes in the metabolism of ethanol were studied in Saccharomyces oviformis WH92 and its mutants, which grew poorly or not at all on ethanol. The strains, which did not grow on ethanol, did not form HKH from alpha-ketoglutarate and acetaldehyde enzymatically and were also devoid of the alpha-ketoglutarate dehydrogenase complex. Acetaldehyde inhibited the activity of alpha-ketoglutarate dehydrogenase. These mutants did not grow on acetate since they had no acetyl-CoA synthetase activity. The relationship of the formation of HKH with the metabolism of ethanol is discussed.
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PMID:Absence of 5-Hydroxy-4-Ketohexanoate and the alpha-Ketoglutarate Dehydrogenase Complex in Mutants of Saccharomyces oviformis Incapable of Growing on Ethanol. 1634 85

Understanding the structure-activity relationships of catalytic solids has always been hampered by the complexity and nonuniform structures of catalyst particles. Materials based on well-defined colloidal metal particles are ideal model solids to investigate such structure-activity relationships. A new paper by Tsang et al. in this issue indicates that highly selective alpha,beta-unsaturated aldehyde hydrogenation Pt-based catalysts can be obtained following the decoration of Pt nanocrystals with a second metal. The effects of the particle size, substrate shape, and electronic modifications were related to the sample activity. The possibility of depositing these tailor-made colloidal particles onto conventional supports opens exciting new routes toward rational catalyst design and ultraselective catalytic processes.
ACS Nano 2008 Dec 23
PMID:Bridging the gap between surface science and industrial catalysis. 1920 91

It is known that protein attachment to surfaces depends sensitively upon the local structure and environment of the binding sites at the nanometer scale. Using nanografting and reversal nanografting, both atomic force microscopy (AFM)-based lithography techniques, protein binding sites with well-defined local environments are designed and engineered with nanometer precision. Three proteins, goat antibiotin immunoglobulin G (IgG), lysozyme, and rabbit immunoglobulin G, are immobilized onto these engineered surfaces. Strong dependence on the dimension and spatial distribution of protein binding sites are revealed in antibody recognition, covalent attachment via primary amine residues and surface-bound aldehyde groups. This investigation indicates that AFM-based nanolithography enables the production of protein nanostructures, and more importantly, protein-surface interactions at a molecular level can be regulated by changing the binding domains and their local environment at nanometer scale.
ACS Nano 2008 Nov 25
PMID:A nanoengineering approach for investigation and regulation of protein immobilization. 1920 5

Self-assembly of organic molecules on solid surfaces under ultrahigh vacuum conditions has been the focus of intense study, in particular utilizing the technique of scanning tunneling microscopy. The size and complexity of the organic compounds used in such studies are in general limited by thermal decomposition in the necessary vacuum sublimation step. An interesting alternative approach is to deposit smaller molecular precursors, which react with each other on the surface and form the building blocks for the subsequent self-assembly. This has however hitherto not been explored to any significant extent. Here, we perform a condensation reaction between aldehyde and amine precursors codeposited on a Au(111) surface. The reaction product consists of a three-spoke oligo-phenylene-ethynylene backbone with alkyl chains attached through imine coupling. We characterize the self-assembled structures and molecular conformations of the complex reaction product and find that the combined reaction and self-assembly process exhibits pronounced kinetic effects leading to formation of qualitatively different molecular structures depending on the reaction/assembly conditions. At high amine flux/low substrate temperature, compact triimine structures of high conformational order are formed, which inherit organizational motifs from structures formed from one of the reactants. This suggests a topochemical reaction. At low amine flux/high substrate temperature, open porous networks with a high degree of conformational disorder are formed. Both structures are entirely different from that obtained when the triimine product synthesized ex-situ is deposited onto the surface. This demonstrates that the approach of combined self-assembly and on-surface synthesis may allow formation of unique structures that are not obtainable through self-assembly from conventionally deposited building blocks.
ACS Nano 2008 Apr
PMID:Molecular self-assembly from building blocks synthesized on a surface in ultrahigh vacuum: kinetic control and topo-chemical reactions. 1920 95

A novel strategy for creating naturally derived glycan microarrays has been developed. Glycosylamines are prepared from free reducing glycans and stabilized by reaction with acryloyl chloride to generate a glycosylamide in which the reducing monosaccharide has a closed-ring structure. Ozonolysis of the protected glycan yields an active aldehyde, to which a bifunctional fluorescent linker is coupled by reductive amination. The fluorescent derivatives are easily coupled through a residual primary alkylamine to generate glycan microarrays. This strategy preserves structural features of glycans required for antibody recognition and allows development of natural arrays of fluorescent glycans in which the cyclic pyranose structure of the reducing-end sugar residue is retained.
ACS Chem Biol 2009 Sep 18
PMID:Fluorescent glycosylamides produced by microscale derivatization of free glycans for natural glycan microarrays. 1961 66

We developed a unique method for converting atmospheric aldehyde into alcohol using formaldehyde dehydrogenase from Pseudomonas putida (PFDH) doped in a polymer film. A film of poly(2-methacryloyloxyethylphosphorylcholine-co-n-butyl methacrylate) (PMB), which has a chemical structure similar to that of a biological membrane, was employed for its biocompatibility. A water-incorporated polymer film entrapping PFDH and its cofactor NAD(+) was obtained by drying a buffered solution of PMB, PFDH, and NAD(+). The aldehydes in the air were absorbed into the polymer film and then enzymatically oxidized by PFDH doped in the PMB film. Interestingly, alcohol and carboxylic acid were produced by the enzymatic reaction, indicating that PFDH catalyzes dismutation of aldehyde in the PMB film. Importantly, a PFDH-PMB film catalyzes aldehyde degradation without consuming the nucleotide cofactor, thereby allowing repeated use of the film. The activity of PFDH in the PMB film was higher than that in other common water-soluble polymers, suggesting that the hydrational state in a phospholipid polymer matrix is suitable for enzymatic activity.
ACS Appl Mater Interfaces 2009 Feb
PMID:Enzymatic conversion of atmospheric aldehydes into alcohol in a phospholipid polymer film. 2035 5

On the basis of the protection reaction between ethanethiol and aldehyde, we designed and synthesized two new ratiometric fluorescent chemosensors, 3 and 4, by using intramolecular charge transfer (ICT) as a signaling mechanism. Upon the addition of Hg(2+) ion, both probes displayed apparent luminescence color changes, which could be observed by naked eyes under a UV lamp. Unexpectedly, both chemosensors also gave response to the addition of trace silver ions, making this kind of chemosensors as the first example of ratiometric fluorescent probe that showed dual channel fluorescence for both Hg(2+) and Ag(+). The test strips experiments suggested that 3 and 4 could serve as practical fluorescent probes for rapid detection of Hg(2+) ion.
ACS Appl Mater Interfaces 2010 Apr
PMID:A new approach to design ratiometric fluorescent probe for mercury(II) based on the Hg(2+)-promoted deprotection of thioacetals. 2042 27


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