Speciale Gaetano, Thompson Andrew J, Davies Gideon J, Williams Spencer J
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
Curr Opin Struct Biol. 2014 Oct;28:1-13. doi: 10.1016/j.sbi.2014.06.003. Epub 2014 Jul 10.
Glycoside hydrolases (GHs) are classified into >100 sequence-based families. These enzymes process a wide variety of complex carbohydrates with varying stereochemistry at the anomeric and other ring positions. The shapes that these sugars adopt upon binding to their cognate GHs, and the conformational changes that occur along the catalysis reaction coordinate is termed the conformational itinerary. Efforts to define the conformational itineraries of GHs have focussed upon the critical points of the reaction: substrate-bound (Michaelis), transition state, intermediate (if relevant) and product-bound. Recent approaches to defining conformational itineraries that marry X-ray crystallography of enzymes bound to ligands that mimic the critical points, along with advanced computational methods and kinetic isotope effects are discussed.
糖苷水解酶（GHs）被分为100多个基于序列的家族。这些酶能够处理各种在异头碳和其他环位置具有不同立体化学结构的复杂碳水化合物。这些糖类在与它们对应的GHs结合时所呈现的形状，以及在催化反应坐标上发生的构象变化，被称为构象历程。确定GHs构象历程的工作主要集中在反应的关键点上：底物结合态（米氏态）、过渡态、中间体（如相关）和产物结合态。本文讨论了结合模拟关键点的配体的酶的X射线晶体学、先进的计算方法和动力学同位素效应来确定构象历程的最新方法。
