Intermediates of thiamine catalysis immobilized on silica surface as active biocatalysts for alpha-ketoacid decarboxylation
Φόρτωση...
Ημερομηνία
Συγγραφείς
Stamatis, A.
Malandrinos, G.
Butler, I. S.
Hadjiliadis, N.
Louloudi, M.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Molecular Catalysis a-Chemical
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Thiamine-dependent enzymes catalyse the decarboxylation of alpha-ketoacids, by both non-oxidative and oxidative mechanisms. Based on the ability of thiamine-cofactor to catalyse itself the decarboxylation of pyruvate to some extent, we have immobilized on a silica surface two 'active aldehyde' intermediates of thiamine catalysis, 2-alpha-hydroxybenzyl-thiamine pyrophosphate (HBTPP) and 2-alpha-hydroxyethyl-thiamine pyrophosphate (HETPP). The two intermediates have been tethered by a convenient method on silica support via their phosphate groups providing the covalently heterogenised biomolecules [HBTh-OP2O6-SiO3/2](n)center dot xSiO(2), and [HETh-OP2O6-SiO3/2](n)center dot xSiO(2). These bio-composite materials have been evaluated as catalysts for pyruvate and benzoyl-formate decarboxylation in either the presence or not of an aldehyde additive. Our data show that they are stable, very effective and recyclable catalysts for the production of 2-hydroxy-ketones, acetoine and benzoin. Their catalytic behavior is much better than the corresponding behavior of the homogeneous thiamine-systems due to the selected immobilization mode which bears similarities to that of the thiamine-cofactor binding to the protein. Considering our results, possible catalytic pathways of the prepared bio-composite materials are suggested. (C) 2006 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
thiamine catalysis, decarboxylation, immobilised biocatalysts, modified silica, 2-hydroxy-ketones, diphosphate-dependent enzymes, sol-gel materials, benzoylformate decarboxylase, crystal-structure, metal-complexes, pyrophosphate, mechanism, models, cadmium(ii), resolution
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000245880900017
http://ac.els-cdn.com/S1381116906014075/1-s2.0-S1381116906014075-main.pdf?_tid=7c1b87479e8b7a862c552f056d00b985&acdnat=1333034662_fa5d43f85f387379c81307d9bc4dc3e0
http://ac.els-cdn.com/S1381116906014075/1-s2.0-S1381116906014075-main.pdf?_tid=7c1b87479e8b7a862c552f056d00b985&acdnat=1333034662_fa5d43f85f387379c81307d9bc4dc3e0
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας