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Key Catalyst (key + catalyst)
Selected AbstractsSynthesis of Aromatic Aldehydes by Aerobic Oxidation of Hydroaromatic Compounds and Diarylalkanes Using N-Hydroxyphthalimide (NHPI) as a Key Catalyst.CHEMINFORM, Issue 26 2006Yasuhiro Aoki Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Oxidation of Nitrotoluenes with Air Using N-Hydroxyphthalimide Analogues as Key Catalysts.CHEMINFORM, Issue 22 2003Naoko Sawatari Abstract For Abstract see ChemInform Abstract in Full Text. [source] Tourist satisfaction and beyond: tourist migrants in MallorcaINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 2 2008David Bowen Abstract This exploratory study analyses the role of tourist experience, especially tourist satisfaction, in subsequent migration from the UK to the municipality of Calviá, Mallorca, Spain. An overview and commentary is provided of theory relating to both tourist satisfaction and migration. Through a series of elite interviews, in-depth micro-studies and a questionnaire, which provides a small quantitative component, it is established that the motivation given by tourist satisfaction can be recognised as a key catalyst for migration. Classic migration motivations cannot be entirely discounted, and the migration decisions are multi-stage through time. But tourist satisfaction,and particularly the two satisfaction components of performance and emotion,is especially relevant in the micro-perspective of migration decision-making. Copyright © 2008 John Wiley & Sons, Ltd. [source] Probing the active site of MIO-dependent aminomutases, key catalysts in the biosynthesis of ,-amino acids incorporated in secondary metabolitesBIOPOLYMERS, Issue 9 2010Heather A. Cooke Abstract The tyrosine aminomutase SgTAM produces (S)-ß-tyrosine from L -tyrosine in the biosynthesis of the enediyne antitumor antibiotic C-1027. This conversion is promoted by the methylideneimidazole-5-one (MIO) prosthetic group. MIO was first identified in the homologous family of ammonia lyases, which deaminate aromatic amino acids to form ,,ß-unsaturated carboxylates. Studies of substrate specificity have been described for lyases but there have been limited reports in altering the substrate specificity of aminomutases. Furthermore, it remains unclear as to what structural properties are responsible for catalyzing the presumed readdition of the amino group into the ,,ß-unsaturated intermediates to form ß-amino acids. Attempts to elucidate specificity and mechanistic determinants of SgTAM have also proved to be difficult as it is recalcitrant to perturbations to the active site via mutagenesis. An X-ray cocrystal structure of the SgTAM mutant of the catalytic base with L -tyrosine verified important substrate binding residues as well as the enzymatic base. Further mutagenesis revealed that removal of these crucial interactions renders the enzyme inactive. Proposed structural determinants for mutase activity probed via mutagenesis, time-point assays and X-ray crystallography revealed a complicated role for these residues in maintaining key quaternary structure properties that aid in catalysis. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 802,810, 2010. [source] | ||||||||||