Positional specificity of Flavobacterium johnsoniae acetylxylan esterase and acetyl group migration on xylan main chain.

Autor: Puchart V; Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic. Electronic address: vladimir.puchart@savba.sk., Gjermansen M; Novozymes A/S, Kogshoejvej 36, DK-2880 Bagsvaerd, Denmark. Electronic address: mgjm@novozymes.com., Mastihubová M; Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic. Electronic address: maria.mastihubova@savba.sk., Mørkeberg Krogh KBR; Novozymes A/S, Kogshoejvej 36, DK-2880 Bagsvaerd, Denmark. Electronic address: KBK@novozymes.com., Biely P; Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic. Electronic address: peter.biely@savba.sk.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2020 Mar 15; Vol. 232, pp. 115783. Date of Electronic Publication: 2019 Dec 24.
DOI: 10.1016/j.carbpol.2019.115783
Abstrakt: A new Flavovacterium johnsoniae isolate encodes an enzyme that is essentially identical with a recently discovered novel acetylxylan esterase, capable of liberating 3-O-acetyl group from 4-O-methyl-d-glucuronic acid-substituted xylopyranosyl (Xylp) residues (Razeq et al., 2018). In addition to deesterification of the 2-O-MeGlcA-substituted Xylp residues in acetylglucuronoxylan, the enzyme acts equally well on doubly acetylated Xylp residues from which it liberates only the 3-O-acetyl groups, leaving the 2-O-acetyl groups untouched. 3-O-Monoacetylated Xylp residues are attacked with a significantly reduced affinity. The resulting 2-O-acetylated xylan was used to investigate for the first time the migration of the 2-O-acetyl group to position 3 within the polysaccharide. In contrast to easy acetyl group migration along the monomeric xylopyranosides or non-reducing-end terminal Xylp residues of xylooligosaccharides, such a migration in the polymer required much longer heating at 100 °C. The specificity of the xylan 3-O-deacetylase was, however, no so strict on acetylated methyl and 4-nitrophenyl xylopyranosides.
(Copyright © 2019 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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