Journal article

An atypical interaction explains the high-affinity of a non-hydrolyzable S-linked 1,6-alpha-mannanase inhibitor

Tyson Belz, Yi Jin, Joan Coines, Carme Rovira, Gideon J Davies, Spencer J Williams



The non-hydrolyzable S-linked azasugars, 1,6-α-mannosylthio- and 1,6-α-mannobiosylthioisofagomine, were synthesized and shown to bind with high affinity to a family 76 endo-1,6-α-mannanase from Bacillus circulans. X-ray crystallography showed an atypical interaction of the isofagomine nitrogen with the catalytic acid/base. Molecular dynamics simulations reveal that the atypical binding results from sulfur perturbing the most stable form away from the nucleophile interaction preferred for the O-linked congener.

University of Melbourne Researchers


Awarded by European Research Council

Awarded by Australian Research Council

Awarded by Spanish Ministry of Economy, Industry and Competitiveness (MINECO)

Awarded by Generalitat de Catalunya-AGAUR

Awarded by Biotechnology and Biological Sciences Research Council

Funding Acknowledgements

We are supported by the Royal Society (Ken Murray Research professorship to G. J. D.), the European Research Council (ERC-2012-AdG-32294 "Glycopoise'' to G. J. D. and Y. J.), the Australian Research Council (FT130100103) (S. J. W.), the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, CTQ2014-55174-P) (C. R. and J. C.) and Generalitat de Catalunya-AGAUR (2014SGR-987) (C. R.). We thank Diamond Light Source for access to beamline I02 and I04 (mx-13587), BSC-CNS for computer resources and technical support at MareNostrum (RES-QCM-2016-3-0017), and Amicus Therapeutics. J. C. thanks MINECO for a PhD scholarship (FPI).