Anomeric Selectivity of Trehalose Transferase with Rare l-Sugars

Luuk Mestrom; Stefan R Marsden; Hessel van der Eijk; Jesper U Laustsen; Cy M Jeffries; Dmitri I Svergun; Peter-Leon Hagedoorn; Isabel Bento; Ulf Hanefeld

doi:10.1021/acscatal.0c02117

Anomeric Selectivity of Trehalose Transferase with Rare l-Sugars

ACS Catal. 2020 Aug 7;10(15):8835-8839. doi: 10.1021/acscatal.0c02117. Epub 2020 Jul 22.

Authors

Luuk Mestrom¹, Stefan R Marsden¹, Hessel van der Eijk¹, Jesper U Laustsen², Cy M Jeffries², Dmitri I Svergun², Peter-Leon Hagedoorn¹, Isabel Bento², Ulf Hanefeld¹

Affiliations

¹ Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands.
² European Molecular Biology Laboratory, EMBL, Hamburg Unit, Notkestraβe 85, 22607 Hamburg, Germany.

Abstract

Retaining LeLoir glycosyltransferases catalyze the formation of glycosidic bonds between nucleotide sugar donors and carbohydrate acceptors. The anomeric selectivity of trehalose transferase from Thermoproteus uzoniensis was investigated for both d- and l-glycopyranose acceptors. The enzyme couples a wide range of carbohydrates, yielding trehalose analogues with conversion and enantioselectivity of >98%. The anomeric selectivity inverts from α,α-(1 → 1)-glycosidic bonds for d-glycopyranose acceptors to α,β-(1 → 1)-glycosidic bonds for l-glycopyranose acceptors, while (S)-selectivity was retained for both types of sugar acceptors. Comparison of protein crystal structures of trehalose transferase in complex with α,α-trehalose and an unnatural α,β-trehalose analogue highlighted the mechanistic rationale for the observed inversion of anomeric selectivity.