Self-assembly immobilization of a universal catalytic microreactor for glycosyltransferases

Abstract

Hyaluronic acid (HA) and chondroitin sulfate (CS) are polydisperse glycosaminoglycans (GAGs),which have important applications as health care products and drugs in skin beauty and arthritis prevention. Enzymatic synthesis is a significant strategy to obtain oligosaccharides and polysaccharides with uniform chain length and well-defined structure. However, the limitations of glycosyltransferase, such as low expression, poor stability, and difficulty in reuse, greatly restrict its application in large-scale commercial production. In this study, we constructed the expression system for hyaluronic acid synthase PmHAS and chondroitin synthase KfoC to obtain the enzyme with high expression level and good water solubility. Subsequently, we screened and optimized several highly biocompatible metal-organic frameworks (MOFs) to immobilize two glycosyltransferases efficiently. The resulting enzyme@MOF composite can catalyze the synthesis of hyaluronic acid and chondroitin oligosaccharides/polysaccharides in quantitative yield. Meanwhile, the supramolecular interactions between enzyme and hydrophilic MOFs confer satisfactory stability, durability, and reusability on immobilized PmHAS and KfoC.