Premium
Efficient Method for the Elongation of the N ‐Acetylglucosamine Unit by Combined Use of Chitinase and β ‐Galactosidase
Author(s) -
Shoda Shinichiro,
Fujita Masaya,
Lohavisavapanichi Chakapan,
Misawa Yoshinori,
Ushizaki Koushin,
Tawata Yukiko,
Kuriyama Mao,
Kohri Michinari,
Kuwata Hideyuki,
Watanabe Takeshi
Publication year - 2002
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(200211)85:11<3919::aid-hlca3919>3.0.co;2-p
Subject(s) - chemistry , regioselectivity , chitinase , glycosidic bond , glycosylation , n acetylglucosamine , galactosyltransferase , stereochemistry , glycosyl donor , oligosaccharide , stereoselectivity , glycoside hydrolase , glycosyl , hydrolysis , enzyme , organic chemistry , catalysis , biochemistry
A novel strategy for the regio‐ and stereoselective synthesis by two enzymatic steps of oligosaccharides having an N ‐acetylglucosamine unit at the nonreducing end was developed. The first step involves a chitinase‐catalyzed highly selective β ‐ N ‐acetyllactosamination of an oligosaccharide acceptor with a 4,5‐dihydrooxazole derivative of N ‐acetyllactosamine as the glycosyl donor. The usage of a transition‐state‐analogue substrate for the chitinase under basic conditions allows the reaction to proceed only in the synthetic direction while suppressing hydrolysis of the product in aqueous media. Several chitinase mutants also catalyzed the glycosylation efficiently under neutral conditions. The second step is a regioselective cleavage of the glycosidic bond between the terminal galactose unit and the adjacent N ‐acetylglucosamine unit by the action of a β ‐galactosidase. This constitutes a very useful method to add an N ‐acetylglucosamine unit to the nonreducing end of chito‐ and cello‐oligosaccharide derivatives in a regio‐ and stereoselective manner.