Enzymatic synthesis of 3-deoxy-D-manno-octulosonic acid (KDO) and its application for LPS assembly

The studies of 3-deoxy-D-manno-octulosonic acid (KDO) have been hindered due to its limited availability. Herein, an efficient enzymatic system for the facile synthesis of KDO from easy-to-get starting materials is described. In this one-pot three-enzyme (OPME) system, D-ribulose 5-phosphate, which was prepared from D-xylose, was employed as starting materials. The reaction process involves the isomerization of D-ribulose 5-phosphate to D-arabinose 5-phosphate catalyzed by D-arabinose 5-phosphate isomerase (KdsD), the aldol condensation of D-arabinose 5-phosphate and phosphoenolpyruvate (PEP) catalyzed by KDO 8-phosphate synthetase (KdsA), and the hydrolysis of KDO-8-phosphate catalyzed by KDO 8-phosphate phosphatase (KdsC). By using this OPME system, 72% isolated yield was obtained. The obtained KDO was further transferred to lipid A by KDO transferase from Escherichia coli (WaaA). (C) 2016 Elsevier Ltd. All rights reserved.