Detection of molecular behavior that characterizes systems using a deep learning approach.

Molecular dynamics (MD) simulation is a powerful computational method to observe molecular behavior. Although the detection of molecular behavior that characterizes systems is an important task in the study of MD, it is typically difficult and depends on human expert knowledge. Therefore, we propose a novel analysis scheme for MD data using deep neural networks.

Molecular Dynamic Simulations to Probe Water Permeation Pathways of GPCRs.

Rhodopsin is a light-driven G protein-coupled receptor mediating signal transduction in eyes. The molecular dynamics (MD) simulations are powerful computational tools to investigate molecular behavior of proteins and internal water molecules which are related to the function of proteins; however, the MD simulations of the rhodopsin require several technical setups for accurate calculations. This chapter discusses practical methods for setting up the MD simulations of the rhodopsin [preparation of initial systems, condition files for MD simulation package GROMACS, and data analysis].

Detection of Anomalous Dynamics for a Single Water Molecule.

Water dynamics is of predominant importance in life, and it plays a critical role in chemical and biological systems. Many studies have reported nonbulk and anomalous dynamics of water molecules; however, a general method to detect the anomalous dynamics is yet to be established. Here, we develop a detection approach for the anomalous dynamics of a water molecule.

Origin of the blueshift of water molecules at interfaces of hydrophilic cyclic compounds.

Water molecules at interfaces of materials exhibit enigmatic properties. A variety of spectroscopic studies have observed a high-frequency motion in these water molecules, represented by a blueshift, at both hydrophobic and hydrophilic interfaces. However, the molecular mechanism behind this blueshift has remained unclear.

Effects of temperature, concentration, and isomer on the hydration structure in monosaccharide solutions.

Water-monosaccharide coupled interactions are essential for the function, stability, and dynamics of all glycans. Using molecular dynamics simulations, we investigated the effects of temperature, concentration, and monosaccharide isomer on the hydration structure and water dynamics in the hydration shell of monosaccharides in solution. We found that perturbations of the hydrogen-bond (H-bond) network in the first hydration shell around each monosaccharide molecule can be separated into two regions: one rich in water molecules with donor H-bonds (in the 2.

Water permeation through the internal water pathway in activated GPCR rhodopsin.

Rhodopsin is a light-driven G-protein-coupled receptor that mediates signal transduction in eyes. Internal water molecules mediate activation of the receptor in a rhodopsin cascade reaction and contribute to conformational stability of the receptor. However, it remains unclear how internal water molecules exchange between the bulk and protein inside, in particular through a putative solvent pore on the cytoplasmic.

Water confined in the local field of ions.

Interionic distances are shorter in concentrated ionic solutions, thus instigating the interaction and overlap of hydration shells, as ions become separated by only one or two layers of water molecules. The simultaneous interaction of water with two oppositely charged ions has, so far, only been investigated by computer simulation studies, because the isolated vibrational spectroscopic signature of these molecules remains undetected. Our combined near-infrared spectroscopic and molecular dynamics simulation studies of alkali halide solutions present a distinct spectral feature, which is highly responsive to depletion of bulk water and merging of hydration shells.