Acetyl xylan esterase-catalyzed deacetylation of chitin and chitosan

Autor:	François Shareck, Grégory Chauve, Romas J. Kazlauskas, Claude Dupont, Robert H. Marchessault, Krista L. Morley
Rok vydání:	2006
Předmět:	Polymers and Plastics biology Stereochemistry Organic Chemistry Substrate (chemistry) macromolecular substances Enzyme assay Enzyme catalysis Chitosan Hydrolysis chemistry.chemical_compound chemistry Chitin Acetylation Materials Chemistry biology.protein Organic chemistry Acetylxylan esterase
Zdroj:	Carbohydrate Polymers. 63:310-315
ISSN:	0144-8617
DOI:	10.1016/j.carbpol.2005.07.034
Popis:	Acetyl xylan esterase catalyzes the hydrolysis of N-acetyl groups in chitinous materials of variable degrees of polymerization and acetylation. The influence of substrate accessibility is most notable with substrate of high degree of acetylation (DA). The activity rises sharply as the number of acetyl groups in the substrates decreases and at about 24% DA enzyme activity reaches a maximum. Therefore, based on a multiple-attack mechanism we hypothesize that this maximum represents the ideal acetate microstructure for optimal activity of this enzyme. The enzyme partially deacetylates chitin oligomers DP 2–6 with a plateau in deacetylation observed at DP5. These results show that oligomer length is important for enzyme action. By combining successive alkaline and enzymatic deacetylation a process improvement for production of chitosan is suggested.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1250d8b0df9d0077e112874cc31bd15e https://doi.org/10.1016/j.carbpol.2005.07.034 Zobrazit plný text záznamu Full Text from ScienceDirect