TY - JOUR
T1 - Characterization of a thermostable family 10 endo-xylanase (XynB) from Thermotoga maritima that cleaves p-nitrophenyl-β-D-xyloside
AU - Zhengqiang, Jiang
AU - Kobayashi, Atsushi
AU - Ahsan, Mohammad Mainul
AU - Lite, Li
AU - Kitaoka, Motomitsu
AU - Hayashi, Kiyoshi
PY - 2001
Y1 - 2001
N2 - Thermotoga maritima MSB8 possesses two xylanase genes, xynA and xynB. The xynB gene was isolated from the genomic DNA of T. maritima, cloned, and expressed in Escherichia coli. XynB was purified to homogeneity by heat treatment, affinity chromatography and ion-exchange column chromatography. The purified enzyme produced a single band upon SDS-PAGE corresponding to a molecular mass of 42 kDa. At 70°C, the enzyme was stable between pH 5.0 and pH 11.4, and it was stable at temperatures of up to 100°C from pH 7.0 to pH 8.5. At 50°C, XynB displayed an optimum pH of 6.14 and at this pH the temperature for optimal enzyme activity was 90°C. XynB exhibited broad substrate specificity and was highly active towards p-nitrophenyl-β-D-xylobioside with Km and kcat values of 0.0077 mM and 5.5 s-1, respectively, at 30°C. It was also active towards p-nitrophenyl-β-D-xyloside. The initial product of the cleavage of p-nitrophenyl-β-D-xyloside was xylobiose, indicating that the major reaction in the cleavage was transglycosylation, not hydrolysis.
AB - Thermotoga maritima MSB8 possesses two xylanase genes, xynA and xynB. The xynB gene was isolated from the genomic DNA of T. maritima, cloned, and expressed in Escherichia coli. XynB was purified to homogeneity by heat treatment, affinity chromatography and ion-exchange column chromatography. The purified enzyme produced a single band upon SDS-PAGE corresponding to a molecular mass of 42 kDa. At 70°C, the enzyme was stable between pH 5.0 and pH 11.4, and it was stable at temperatures of up to 100°C from pH 7.0 to pH 8.5. At 50°C, XynB displayed an optimum pH of 6.14 and at this pH the temperature for optimal enzyme activity was 90°C. XynB exhibited broad substrate specificity and was highly active towards p-nitrophenyl-β-D-xylobioside with Km and kcat values of 0.0077 mM and 5.5 s-1, respectively, at 30°C. It was also active towards p-nitrophenyl-β-D-xyloside. The initial product of the cleavage of p-nitrophenyl-β-D-xyloside was xylobiose, indicating that the major reaction in the cleavage was transglycosylation, not hydrolysis.
KW - Characterization
KW - Thermotoga maritima
KW - Transglycosylation
KW - Xylanase B
UR - http://www.scopus.com/inward/record.url?scp=0035667287&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035667287&partnerID=8YFLogxK
U2 - 10.1016/S1389-1723(01)80290-5
DO - 10.1016/S1389-1723(01)80290-5
M3 - Article
C2 - 16233122
AN - SCOPUS:0035667287
VL - 92
SP - 423
EP - 428
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
SN - 1389-1723
IS - 5
ER -