Water is a ubiquitous and often understudied constituent of the cellular environment. Proteins influence the properties of the aqueous solvent molecules which immerse them, impacting water’s structure, dynamics, and, as recently reported, supramolecular chirality. Hydrogen bonds link individual water molecules into a supramolecular network, and biomolecular solutes can influence water’s hydrogen bonding structure. Molecular dynamics simulations investigate water networks with detailed spatiotemporal resolution. Statistical mechanical order parameters distill microscopic properties of complex systems into statistics providing physical insight. Order parameters facilitate interpreting patterns in large water solvent networks and help develop a framework for understanding the perturbations in water structure accompanying solute addition.<br/><br/>Water’s network architecture was analyzed as a graph, with individual water molecule nodes connected by hydrogen bond edges. Rings are one common network motif, in which hydrogen bonds between adjacent water molecules create a cycle of waters. The properties of an aqueous protein solute have previously been reported to influence surrounding solvent cycle structure. Methodology was developed for finding cycles in an atomistic water solvent molecular dynamics simulation. The frequency of differently sized cycles was compared, to determine their relevance for water network characterization. Cycles’ hydrogen bond directionality was analyzed, to evaluate how uniformly the hydrogen bonds point in the same direction along the path of a cycle. A possible order parameter characterizing water cycles was developed. Understanding water cycle properties and how they change in response to a biomolecule can pave the way to rationally employing solvent environment effects in therapeutic design.

Simulation studies of the prevalence and properties of water molecule cycles

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.