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Titolo:
Lysozyme inactivation and aggregation in stirred-reactor
Autore:
Colombie, S; Gaunand, A; Lindet, B;
Indirizzi:
Ecole Natl Super Mines, Ctr Reacteurs & Proc, F-75006 Paris, France Ecole Natl Super Mines Paris France F-75006 Proc, F-75006 Paris, France
Titolo Testata:
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
fascicolo: 4-6, volume: 11, anno: 2001,
pagine: 559 - 565
SICI:
1381-1177(20010122)11:4-6<559:LIAAIS>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
ENZYME INACTIVATION; SUBUNIT DISSOCIATION; GLOBULAR-PROTEINS; ORGANIC-SOLVENTS; KINETICS; DENATURATION; DECOMPOSITION; CHYMOTRYPSIN; COAGULATION; INDUCTION;
Keywords:
enzyme inactivation; lysozyme; protein aggregation; stirring; kinetics;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
19
Recensione:
Indirizzi per estratti:
Indirizzo: Lindet, B Ecole Natl Super Mines, Ctr Reacteurs & Proc, 60 Blvd St Michel,F-75006 Paris, France Ecole Natl Super Mines 60 Blvd St Michel Paris France F-75006 e
Citazione:
S. Colombie et al., "Lysozyme inactivation and aggregation in stirred-reactor", J MOL CAT B, 11(4-6), 2001, pp. 559-565

Abstract

Mechanisms of enzyme inactivation and aggregation are still poorly understood. In this work, we are considering the characterisation of both inactivation and aggregation in stirred tank reactor, with lysozyme as the model enzyme. The inactivation kinetics are first order. For stirring speeds in the range of 0-700 rpm, the kinetic constant is found to be proportional to the power brought by the impeller. It suggests that inactivation depends on collisions between enzyme molecules. Efficient collisions between native and inactive molecules induce native molecules to turn into inactive molecules and lead to lysozyme aggregation. During inactivation, enzymes are found to aggregate as shown by light scattering measurements. The structure of aggregates was studied on samples treated for chemical denaturation and reduction. The aggregates are supramolecular edifices, mainly made up of inactivated enzymes linked by weak forces. But aggregates are also made up of dimers and trimers of lysozyme, linked by disulfide bridges. Dimers and trimers are 18% and 5%, respectively, of the total amount of lysozyme aggregates. Whatever the stage of aggregate formation and the initial enzyme concentration are, these aggregates are irreversibly inactivated. Enzyme activity isdefinitely lost even if stirring is stopped and/or temperature decreased. This study points out the importance of hydrodynamics in bioreactors and highlights the nature of the aggregates resulting from the interactions between native and inactive enzymes. (C) 2001 Elsevier Science B.V. All rights reserved.

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Documento generato il 02/04/20 alle ore 02:52:42