Abstract：
Sulfated fucans attract increasing research interests in recent decades for their various physiological activities. Fucanases are indispensable tools for the investigation of sulfated fucans. Herein, a novel GH168 family endo-1,3-fucanase was cloned from the genome of marine bacterium Wenyingzhuangia fucanilytica. The expressed protein Fun168D was a processive endo-acting enzyme. Ultra performance liquid chromatography-high resolution mass spectrum and NMR analyses revealed that the enzyme cleaved the α-1 → 3 bonds between α-l-Fucp(2OSO3-) and α-l-Fucp(2OSO3-) in sulfated fucan from Isostichopus badionotus, and α-1 → 3 bonds between α-l-Fucp(2OSO3-) and α-l-Fucp(2,4OSO3-) in sulfated fucan from Holothuria tubulosa. Fun168D would prefer to accept α-l-Fucp(2,4OSO3-) than α-l-Fucp(2OSO3-) at subsite +1, and could tolerate the absence of fucose residue at subsite +2. The novel cleavage specificity and hydrolysis pattern revealed the presence of diversity within the GH168 family, which would facilitate the development of diverse biotechnological tools for the molecule tailoring of sulfated fucan.
摘要：
近几十年来，硫酸化的岩藻因其各种生理活性而引起了越来越多的研究兴趣。对于硫酸化岩藻聚糖的研究,岩藻酶是不可缺少的工具。在这里，从海洋细菌Wenyingjuangiafucleytica的基因组中克隆了一个新的GH168家族endo-1,3-fucanase。表达的蛋白质Fun168D是一种持续的内效酶。超高效液相色谱-高分辨率质谱和NMR分析显示，该酶裂解了硫酸化岩藻聚糖中α-1-Fucp（2OSO3-）和α-1-Fucp（2OSO3-）之间的α-1→3键，和α-1-Fucp（2OSO3-）和α-1-Fucp（2,4OSO3-）之间的α-1→3键。Fun168D更喜欢在子位1接受α-1-Fucp（2,4OSO3-）而不是α-1-Fucp（2OSO3-），并且可以耐受子位2不存在岩藻糖残基。新的裂解特异性和水解模式揭示了GH168家族中多样性的存在，这将有助于开发各种生物技术工具来定制硫酸化的岩藻聚糖。
