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https://hdl.handle.net/2115/87740

Discovery of alpha-L-ucosidase Raises the Possibility of alpha-L-Glucosides in Nature

英語

2022-12-09

American Chemical Society

ACS Omega

7(50)

47411-47423

Glucose, a common monosaccharide in nature, is dominated by the D-enantiomer. Meanwhile, the discovery of L-glucose-utilizing bacteria and the elucidation of their metabolic pathways 10 years ago suggests that L-glucose exists naturally. Most carbohydrates exist as glycosides rather than monosaccharides; therefore, we expected that nature also contains L-glucosides. Sequence analysis within glycoside hydrolase family 29 led us to identify two alpha-L-glucosidases, ClAg129A and ClAg1298, derived from Cecernbia lonarensis LW9. ClAg129A and ClAg129B exhibited higher K-m, k(cat), and k(cat)/K-m values for p-nitrophenyl alpha-L-glucoside than that for p-nitrophenyl alpha-L-fucoside. Structural analysis of ClAg129B in complex with L-glucose showed that these enzymes have an active-site pocket that preferentially binds alpha-L-glucoside, but exdudes alpha-L-fucoside. These results suggest that CIAg129A and ClAg129B evolved to hydrolyze alpha-L-glucoside, implying the existence of alpha-L-glucoside in nature. Furthermore, alpha-L-glucosidic linkages (alpha-L-Glc-(1 -> 3)-L-G1c, alpha-L-Glc-(1 -> 2)-L-Glc, and alpha-L-Glc-(1 -> 6)-L-G1c) were synthesized by the transglucosylation activity of ClAg129A and ClAg129B. We believe that this study will lead to new research on alpha-L-glucosides, including determining the physiological effects on humans, and the discovery of novel alpha-L-ucoside-related enzymes.

学術雑誌論文

Version of Record

2470-1343