Molecular and Biochemical Analyses of a Novel Trifunctional Endoxylanase/Endoglucanase/Feruloyl Esterase from the Human Colonic Bacterium Bacteroides intestinalis DSM 17393
Molecular and Biochemical Analyses of a Novel Trifunctional Endoxylanase/Endoglucanase/Feruloyl Esterase from the Human Colonic Bacterium Bacteroides intestinalis DSM 17393
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DOI：
10.1021/acs.jafc.2c01019
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发表时间：
2022-04-06
影响因子：
6.1
通讯作者：
Wang, Kui
中科院分区：
文献类型：
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作者：
Zhang, Ruiqin;Lin, Dongxia;Wang, Kui
鉴定了一种新的酶Bi 76，该酶由GH 10、E_set_Esterase_N和CE 1三个模块组成，与木聚糖内切酶/阿魏酸酯酶双功能酶的同源性最高（62.9%）。有趣的是，Bi 76除了水解木聚糖和阿魏酸化底物外，还水解葡聚糖底物，这表明它是第一个被表征的三功能内切木聚糖酶/内切葡聚糖酶/阿魏酸酯酶。对截短突变体的分析表明，GH 10和E_set_Esterase_N + CE 1模块分别编码内切木聚糖酶/内切葡聚糖酶和阿魏酸酯酶活性。协同作用分析表明，内切木聚糖酶，α-L-阿拉伯呋喃糖苷酶和阿魏酸酯酶协同作用，从阿魏酸化阿拉伯木聚糖中释放阿魏酸（FA）和低聚木糖。Bi 76的结构域间协同效应大于TM 1和TM 2的分子间协同效应。Bi 76具有较好的产酸能力，从玉米麸皮、玉米芯、麦麸、玉米秸秆、稻壳和米糠中分别释放出5.20、4.38、2.12、1.35、0.46和0.19 mg/g的FA。本研究扩展了三功能内切木聚糖酶/内切葡聚糖酶/阿魏酸酯酶的谱，并展示了Bi 76在农业剩余物利用中的巨大潜力。
A novel enzyme Bi76 comprising GH10, E_set_Esterase_N, and CE1 modules was identified, with the highesthomology (62.9%) with a bifunctional endoxylanase/feruloyl esterase among characterized enzymes. Interestingly, Bi76 hydrolyzedglucan substrates besides xylans and feruloylated substrates, suggesting that it is thefirst characterized trifunctional endoxylanase/endoglucanase/feruloyl esterase. Analyses of truncation variants revealed that GH10 and E_set_Esterase_N + CE1 modulesencoded endoxylanase/endoglucanase and feruloyl esterase activities, respectively. Synergism analyses indicated that endoxylanase,alpha-L-arabinofuranosidase, and feruloyl esterase acted cooperatively in releasing ferulic acid (FA) and xylooligosaccharides fromferuloylated arabinoxylan. The interdomain synergism of Bi76 overmatched the intermolecular synergism of TM1 and TM2.Importantly, Bi76 exhibited good capacity in producing FA, releasing 5.20, 4.38, 2.12, 1.35, 0.46, and 0.19 mg/g from corn bran,corn cob, wheat bran, corn stover, rice husk, and rice bran, respectively. This study expands the trifunctional endoxylanase/endoglucanase/feruloyl esterase repertoire and demonstrates the great potential of Bi76 in agricultural residue utilization.