Males Alexandra, Kok Ken, Nin-Hill Alba, de Koster Nicky, van den Beukel Sija, Beenakker Thomas J M, van der Marel Gijsbert A, Codée Jeroen D C, Aerts Johannes M F G, Overkleeft Herman S, Rovira Carme, Davies Gideon J, Artola Marta
York Structural Biology Laboratory, Department of Chemistry, The University of York York YO10 5DD UK
Department of Medical Biochemistry, Leiden Institute of Chemistry (LIC), Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands
Chem Sci. 2023 Nov 17;14(46):13581-13586. doi: 10.1039/d3sc05016e. eCollection 2023 Nov 29.
Class I inverting exo-acting α-1,2-mannosidases (CAZY family GH47) display an unusual catalytic itinerary featuring ring-flipped mannosides, → → . Conformationally locked compounds, such as kifunensine, display nanomolar inhibition but large multigene GH47 mannosidase families render specific "isoform-dependent" inhibition impossible. Here we develop a bump-and-hole strategy in which a new mannose-configured 1,6--cyclic sulfamidate inhibits α-d-mannosidases by virtue of its conformation. This compound does not inhibit the wild-type GH47 model enzyme by virtue of a steric clash, a "bump", in the active site. An L310S (a conserved residue amongst human GH47 enzymes) mutant of the model GH47 awoke 574 nM inhibition of the previously dormant inhibitor, confirmed by structural analysis of a 0.97 Å structure. Considering that L310 is a conserved residue amongst human GH47 enzymes, this work provides a unique framework for future biotechnological studies on -glycan maturation and ER associated degradation by isoform-specific GH47 α-d-mannosidase inhibition through a bump-and-hole approach.
I类反向外切α-1,2-甘露糖苷酶（CAZY家族GH47）呈现出一种不同寻常的催化途径，其特征为环翻转的甘露糖苷，→ → 。构象锁定的化合物，如 kifunensine，表现出纳摩尔级别的抑制作用，但庞大的多基因GH47甘露糖苷酶家族使得特异性的“异构体依赖性”抑制变得不可能。在此，我们开发了一种“凹凸互补”策略，其中一种新的具有甘露糖构型的1,6-环氨基磺酸酯凭借其构象抑制α-d-甘露糖苷酶。由于空间冲突，即活性位点中的“凸起”，该化合物不会抑制野生型GH47模型酶。模型GH47的L310S（人类GH47酶中的一个保守残基）突变体对先前无活性的抑制剂产生了574 nM的抑制作用，0.97 Å结构的结构分析证实了这一点。鉴于L310是人类GH47酶中的一个保守残基，这项工作为未来通过“凹凸互补”方法特异性抑制异构体的GH47α-d-甘露糖苷酶来研究N-聚糖成熟和内质网相关降解提供了一个独特的框架。
