Transglycosylation reaction of xylanase B from the hyperthermophilic Thermotoga maritima with the ability of synthesis of tertiary alkyl beta-D-xylobiosides and xylosides.
The recombinant xylanase B (XynB) of Thermotoga maritima MSB8 was characterized and was found to cleave p-nitrophenyl beta-D-xyloside via the transglycosylation reaction in the previous study. XynB was activated in the presence of alcohols, and XynB activity was increased by iso-propanol (2M) to 2.1-fold. This type of activation was investigated and was shown to be due to the transglycosylation activity with p-nitrophenyl beta-D-xylobioside being converted to alkyl beta-D-xylobiosides in the presence of XynB and alcohols. Through the transglycosylation reaction, alkyl beta-xylosides and xylobiosides were simultaneously produced in the presence of xylan and alcohols. Primary alcohols were found to be the best acceptors. The highest yields of alkyl beta-xylosides and xylobiosides were 33% and 50% of the total sugar, respectively. XynB showed a great ability to transfer xylose and xylobiose to secondary alcohol acceptors, and was unique for being able to synthesize the tertiary alkyl beta-xylosides and xylobiosides with high yields of 18.2% and 11.6% of the total sugar, respectively. This is the first report of a xylanase with the ability to synthesize tertiary alkyl beta-xylosides and xylobiosides. The specificity of the beta-linkage was confirmed by the proton nuclear magnetic resonance ((1)H NMR). Thus, XynB of T. maritima appears to be an ideal enzyme for the synthesis of useful alkyl beta-xylosides and xylobiosides.
Jiang
Zhengqiang
Z
Department of Biotechnology, College of Food Science and Nutritional Engineering, China Agricultural University, P.O. Box 294, No. 17 Qinghua Donglu, Haidian District, Beijing 100083, China.
Zhu
Yunping
Y
Li
Lite
L
Yu
Xiaohong
X
Kusakabe
Isao
I
Kitaoka
Motomistu
M
Hayashi
Kiyoshi
K
D000478:Alkylation; D004187:Disaccharides / Q000138:chemical synthesis; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006027:Glycosides / Q000138:chemical synthesis*; D006031:Glycosylation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D020124:Thermotoga maritima / Q000201:enzymology* / Q000235:genetics
D004187:Disaccharides; D006027:Glycosides; D011994:Recombinant Proteins; C010807:xylosides; D043364:Endo-1,4-beta Xylanases