Chemo-enzymatic synthesis of oligosaccharides exploits the diversity of glycosidases and their ability to promote transglycosylation reactions in parallel with hydrolysis. Methods to increase the transglycosylation/hydrolysis ratio include site-directed mutagenesis and medium modification. The former approach was successful in several cases and has provided the best synthetic yields with glycosynthases-mutants at the catalytic nucleophile position that promote transglycosylation with high efficiency, but do not hydrolyze the oligosaccharide products. Several glycosidases have proven recalcitrant to this conversion, thus alternative methods to increase the transglycosylation/hydrolysis ratio by mutation would be very useful. Here we show that a mutant of a β-galactosidase from Alicyclobacillus acidocaldarius in an invariant residue in the active site of the enzymes of this family (glutamic acid 361) carries out efficient transglycosylation reactions on different acceptors only in the presence of external ions with yields up to 177-fold higher than that of the wild type. This is the first case in which sodium azide and sodium formate in combination with site-directed mutagenesis have been used to introduce transglycosylation activity into a glycosidase. These observations will hopefully guide further efforts to generate useful synthases.
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http://dx.doi.org/10.1093/glycob/cwx013 | DOI Listing |
Food Chem
January 2025
Department of Biochemistry, Phramongkutklao College of Medicine, Phramongkutklao Hospital, Bangkok 10400, Thailand. Electronic address:
In this study, maltotriosyl-erythritol (EG) was synthesized as a novel prebiotic candidate via transglycosylation using recombinant amylomaltase (AMase) from Thermus sp. Tapioca starch served as the glucosyl donor, and erythritol as the acceptor. High-performance liquid chromatography (HPLC) revealed an EG yield of 14.
View Article and Find Full Text PDFFood Chem
February 2025
School of Biotechnology and Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China. Electronic address:
Foods
October 2024
Department of Food Science and Nutrition, Dankook University, Cheonan 31116, Republic of Korea.
J Agric Food Chem
September 2024
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
Lacto--triose II (LNTri II), an important precursor for human milk oligosaccharide (HMOs) synthesis, has garnered significant attention due to its structural features and physiological properties. Composed of galactose (Gal), -acetylglucosamine (GlcNAc), and glucose (Glc), with the chemical structure GlcNAcβ1,3Galβ1,4Glc, the distinctive structure of LNTri II confers various physiological functions such as promoting the growth of beneficial bacteria, regulating the infant immune system, and preventing certain gastrointestinal diseases. Extensive research efforts have been dedicated to elucidating efficient enzymatic synthesis pathways for LNTri II production, with particular emphasis on the transglycosylation activity of β--acetylhexosaminidases and the action of β-1,3--acetylglucosaminyltransferases.
View Article and Find Full Text PDFBiomolecules
July 2024
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
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