Comparing the structural dynamics of the human KCNE3 in reconstituted micelle and lipid bilayered vesicle environments.

KCNE3 is a single transmembrane protein of the KCNE family that modulates the function and trafficking of several voltage-gated potassium channels, including KCNQ1. Structural studies of KCNE3 have been previously conducted in a wide range of model membrane mimics. However, it is important to assess the impact of the membrane mimics used on the observed conformation and dynamics. In this study, we have optimized a method for the reconstitution of the KCNE3 into POPC/POPG lipid bilayer vesicles for electron paramagnetic resonance (EPR) spectroscopy. Our CD spectroscopic data suggested that the degree of regular secondary structure for KCNE3 protein reconstituted into lipid bilayered vesicle is significantly higher than in DPC detergent micelles. Electron paramagnetic resonance (EPR) spectroscopy in combination with site-directed spin labeling (SDSL) was used to probe the structural dynamics of S49C, M59C, L67C, V85C, and S101C mutations of KCNE3 in both DPC micelles and in POPC/POPG lipid bilayered vesicles. Our CW-EPR power saturation data suggested that the site S74C is buried inside the lipid bilayered membrane while the site V85C is located outside the membrane, in contrast to DPC micelle results. These results suggest that the KCNE3 micelle structures need to be refined using data obtained in the lipid bilayered vesicles in order to ascertain the native structure of KCNE3. This work will provide guidelines for detailed structural studies of KCNE3 in a more native membrane environment and comparing the lipid bilayer results to the isotropic bicelle structure and to the KCNQ1-bound cryo-EM structure.

Severe Pain in Veteran Students.

BACKGROUND: Severe pain is prevalent in military veterans. Veteran students face significant challenges in attaining academic success. Understanding the impact of pain on learning of veteran students is very important to better advocate for veteran students and promote social responsibility and cultural competence. OBJECTIVE: The objective of the research was to determine pain in veteran students compared to nonveteran students. DESIGN: The research design was a cross-sectional non-experimental survey. METHODS: The survey included a total of 6 questions adapted from the National Health Interview Survey and was administered using SurveyGizmo. RESULTS: Veteran students are 4.3 times more likely to report severe pain than nonveteran students. 98.6% veteran students reported pain and 22.2% had severe pain. 25.0% of veteran students reported the ability to carry out daily work limited by pain. Only 4.2% of veteran students reported sufficient resources on campus helping them deal with pain, while 58.3% reported sufficient resources off campus. CONCLUSIONS: Veteran students had statistically significantly more severe pain. They were more limited by pain in carrying out daily work and reported fewer resources to help them cope with pain. The data can inform strategies for advocacy activities of physical therapists and assessment for culturally competent education.

Long-term weathering and continued oxidation of oil residues from the Deepwater Horizon spill.

To investigate the long-term weathering of oil from the Deepwater Horizon (DWH) incident, oil-soaked sand patties were collected from Gulf of Mexico beaches from Florida to Alabama over a three-year period from 2012 to 2014. Analysis of oil residues by gas chromatography with flame ionization detection (GC-FID), thin-layer chromatography with flame ionization detection (TLC-FID), and Fourier transform infrared spectroscopy (FT-IR) indicated uniformity in their chemical composition. Some variability within and between samples was observed, arising from differences in exposure to light and water, which increase the amount of weathering. Oxygenated hydrocarbons (OxHC) produced by weathering processes dominate the majority of oil residues. These OxHC have continued recalcitrance in the environment, and increase in relative abundance over time. Analyses of the bulk characteristics of oil residues via TLC-FID and FT-IR should be continued as these techniques provide important insight into the weathering state of oil residues.