Uncovering the World of Dietary Supplements and Performance-Enhancing Substances in the Military.

This article highlights key topic areas related to dietary supplements (DSs) and performance-enhancing substances. It also discusses evidence-based resources the medical community can use when discussing high-quality DSs with Servicemembers interested in taking DSs. We briefly overview how DSs are regulated in the United States, discuss problematic categories and issues related to quality, expand upon what are often considered performance-enhancing substances yet sometimes sold as DSs, and then offer solutions to counter the consequences of the dark side of the DS industry.

Analysis of Multidomain Protein Dynamics.

Proteins with a modular architecture of multiple domains connected by linkers often exhibit diversity in the relative positions of domains, while the domain tertiary structure remains unchanged. The biological function of these modular proteins, or the regulation of their activity, depends on the variation in domain orientation and separation. Accordingly, careful characterization of interdomain motion and correlated fluctuations of multidomain systems is relevant for understanding the functional behavior of modular proteins.

Evaluating the dynamics and electrostatic interactions of folded proteins in implicit solvents.

Three implicit solvent models, namely GBMVII, FACTS, and SCPISM, were evaluated for their abilities to emulate an explicit solvent environment by comparing the simulated conformational ensembles, dynamics, and electrostatic interactions of the Src SH2 domain and the Lyn kinase domain. This assessment in terms of structural features in folded proteins expands upon the use of hydration energy as a metric for comparison. All-against-all rms coordinate deviation, average positional fluctuations, and ion-pair distance distribution were used to compare the implicit solvent models with the TIP3P explicit solvent model.

Relative Binding Enthalpies from Molecular Dynamics Simulations Using a Direct Method.

The potential for reliably predicting relative binding enthalpies, ΔΔ, from a direct method utilizing molecular dynamics is examined for a system of three phosphotyrosyl peptides binding to a protein receptor, the Src SH2 domain. The binding enthalpies were calculated from the potential energy differences between the bound and the unbound end-states of each peptide from equilibrium simulations in explicit water. The statistical uncertainties in the ensemble-mean energy values from multiple, independent simulations were obtained using a bootstrap method.