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Publication Abstract from PubMed

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, ClAgl29A and ClAgl29B, derived from Cecembia lonarensis LW9. ClAgl29A and ClAgl29B 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 ClAgl29B in complex with l-glucose showed that these enzymes have an active-site pocket that preferentially binds alpha-l-glucoside, but excludes alpha-l-fucoside. These results suggest that ClAgl29A and ClAgl29B 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-Glc, alpha-l-Glc-(1 --> 2)-l-Glc, and alpha-l-Glc-(1 --> 6)-l-Glc) were synthesized by the transglucosylation activity of ClAgl29A and ClAgl29B. 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-glucoside-related enzymes.

Discovery of alpha-l-Glucosidase Raises the Possibility of alpha-l-Glucosides in Nature.,Shishiuchi R, Kang H, Tagami T, Ueda Y, Lang W, Kimura A, Okuyama M ACS Omega. 2022 Dec 9;7(50):47411-47423. doi: 10.1021/acsomega.2c06991. , eCollection 2022 Dec 20. PMID:36570207^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.