Evidences that β-lactose forms hydrogen bonds in DMSO

Abstract

Glycoproteins and glycolipids play key roles in intracellular reactions between cells and their environments at the membrane surface. For better understanding of the nature of these events, it is necessary to know three-dimensional structures of those carbohydrates, involved in them. Since carbohydrates contain many hydroxyl groups which can serve both as hydrogen bond donors and acceptors, hydrogen bond is an important factor stabilizing the structure of carbohydrate. DMSO is an aprotic solvent frequently used for the study of carbohydrates because it gives detailed insight into the intramolecular hydrogen bond network. In this study, conformational properties and the hydrogen bonds in β-lactose in DMSO are investigated by NMR spectroscopy and molecular dynamics simulations. NOEs, temperature coefficients, deuterium isotope effect, and molecular dynamics simulations proved that there is a strong intramolecular hydrogen bond between O3 and HO2' in β-lactose and also OH3 in β-lactose may form an intermolecular hydrogen bond with DMSO.