TY - JOUR
T1 - A novel acid-tolerant β-xylanase from Scytalidium candidum 3C for the synthesis of o-nitrophenyl xylooligosaccharides
AU - Eneyskaya, Elena V.
AU - Bobrov, Kirill S.
AU - Kashina, Maria V.
AU - Borisova, Anna S.
AU - Kulminskaya, Anna A.
N1 - Funding Information:
Elena V. Eneyskaya, Kirill S. Bobrov, and Anna A. Kulminskaya acknowledge the financial support from the Genome Research Center development program “Kurchatov Genome Center—PNPI” (agreement no. 075‐15‐2019‐1663).
Publisher Copyright:
© 2020 Wiley-VCH GmbH
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/11
Y1 - 2020/11
N2 - Endo-β-xylanases are hemicellulases involved in the conversion of xylans in plant biomass. Here, we report a novel acidophilic β-xylanase (ScXynA) with high transglycosylation abilities that was isolated from the filamentous fungus Scytalidium candidum 3C. ScXynA was identified as a glycoside hydrolase family 10 (GH10) dimeric protein, with a molecular weight of 38 ± 5 kDa per subunit. The enzyme catalyzed the hydrolysis of different xylans under acidic conditions and was stable in the pH range 2.6–4.5. The kinetic parameters of ScXynA were determined in hydrolysis reactions with p-nitrophenyl-β-d-cellobioside (pNP-β-Cel) and p-nitrophenyl-β-d-xylobioside (pNP-β-Xyl2), and kcat/Km was found to be 0.43 ± 0.02 (s·mM)−1 and 57 ± 3 (s·mM)−1, respectively. In the catalysis of the transglycosylation o-nitrophenyl-β-d-xylobioside (oNP-β-Xyl2) acted both as a donor and an acceptor, resulting in the efficient production of o-nitrophenyl xylooligosaccharides, with a degree of polymerization of 3–10 and o-nitrophenyl-β-d-xylotetraose (oNP-β-Xyl4) as the major product (18.5% yield). The modeled ScXynA structure showed a favorable position for ligand entry and o-nitrophenyl group accommodation in the relatively open −3 subsite, while the cleavage site was covered with an extended loop. These structural features provide favorable conditions for transglycosylation with oNP-β-Xyl2. The acidophilic properties and high transglycosylation activity make ScXynA a suitable choice for various biotechnological applications, including the synthesis of valuable xylooligosaccharides.
AB - Endo-β-xylanases are hemicellulases involved in the conversion of xylans in plant biomass. Here, we report a novel acidophilic β-xylanase (ScXynA) with high transglycosylation abilities that was isolated from the filamentous fungus Scytalidium candidum 3C. ScXynA was identified as a glycoside hydrolase family 10 (GH10) dimeric protein, with a molecular weight of 38 ± 5 kDa per subunit. The enzyme catalyzed the hydrolysis of different xylans under acidic conditions and was stable in the pH range 2.6–4.5. The kinetic parameters of ScXynA were determined in hydrolysis reactions with p-nitrophenyl-β-d-cellobioside (pNP-β-Cel) and p-nitrophenyl-β-d-xylobioside (pNP-β-Xyl2), and kcat/Km was found to be 0.43 ± 0.02 (s·mM)−1 and 57 ± 3 (s·mM)−1, respectively. In the catalysis of the transglycosylation o-nitrophenyl-β-d-xylobioside (oNP-β-Xyl2) acted both as a donor and an acceptor, resulting in the efficient production of o-nitrophenyl xylooligosaccharides, with a degree of polymerization of 3–10 and o-nitrophenyl-β-d-xylotetraose (oNP-β-Xyl4) as the major product (18.5% yield). The modeled ScXynA structure showed a favorable position for ligand entry and o-nitrophenyl group accommodation in the relatively open −3 subsite, while the cleavage site was covered with an extended loop. These structural features provide favorable conditions for transglycosylation with oNP-β-Xyl2. The acidophilic properties and high transglycosylation activity make ScXynA a suitable choice for various biotechnological applications, including the synthesis of valuable xylooligosaccharides.
KW - glycoside hydrolase family 10
KW - o-nitrophenyl xylooligosaccharides
KW - transglycosylation
KW - β-xylanase
UR - http://www.scopus.com/inward/record.url?scp=85093929730&partnerID=8YFLogxK
U2 - 10.1002/jobm.202000303
DO - 10.1002/jobm.202000303
M3 - Article
C2 - 33103248
AN - SCOPUS:85093929730
SN - 0233-111X
VL - 60
SP - 971
EP - 982
JO - Journal of Basic Microbiology
JF - Journal of Basic Microbiology
IS - 11-12
ER -