Differential effects of oligosaccharides on the hydration of simple cations

Changed ion hydration properties near surfaces, proteins, and deoxyribose nucleic acid have been reported before in the literature. In the present work, we extend this work to carbohydrates: We have performed classical-mechanical molecular dynamics simulations to study solvation properties of simple cations of biological relevance (Na+,K+,Mg2+,Ca2+) in explicit water, near single and multiple oligosaccharides as glycocalyx models. We find that our oligosaccharides prefer direct contact with K+ over Na+, but that the Na+ contacts are longer lived. These interactions also lead to strong but short-lived changes in oligosaccharide conformations, with oligosaccharides wrapping around K+ with multiple contacts. These findings may have implications for current hypotheses on glycocalyx functions. (c) 2008 American Institute of Physics.