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KCNE3 is a single-pass integral membrane protein that regulates numerous voltage-gated potassium channel functions such as KCNQ1. Previous solution NMR studies suggested a moderate degree of curved α-helical structure in the transmembrane domain (TMD) of KCNE3 in lyso-myristoylphosphatidylcholine (LMPC) micelles and isotropic bicelles with the residues T71, S74 and G78 situated along the concave face of the curved helix. During the interaction of KCNE3 and KCNQ1, KCNE3 pushes its transmembrane domain against KCNQ1 to lock the voltage sensor in its depolarized conformation. A cryo-EM study of KCNE3 complexed with KCNQ1 in nanodiscs suggested a deviation of the KCNE3 structure from its independent structure in isotropic bicelles. Despite the biological significance of KCNE3 TMD, the conformational properties of KCNE3 are poorly understood. Here, all atom molecular dynamics (MD) simulations were utilized to investigate the conformational dynamics of the transmembrane domain of KCNE3 in a lipid bilayer containing a mixture of POPC and POPG lipids (3:1). Further, the effect of the interaction impairing mutations (V72A, I76A and F68A) on the conformational properties of the KCNE3 TMD in lipid bilayers was investigated. Our MD simulation results suggest that the KCNE3 TMD adopts a nearly linear α helical structural conformation in POPC-POPG lipid bilayers. Additionally, the results showed no significant change in the nearly linear α-helical conformation of KCNE3 TMD in the presence of interaction impairing mutations within the sampled time frame. The KCNE3 TMD is more stable with lower flexibility in comparison to the N-terminal and C-terminal of KCNE3 in lipid bilayers. The overall conformational flexibility of KCNE3 also varies in the presence of the interaction-impairing mutations. The MD simulation data further suggest that the membrane bilayer width is similar for wild-type KCNE3 and KCNE3 containing mutations. The Z-distance measurement data revealed that the TMD residue site A69 is close to the lipid bilayer center, and residue sites S57 and S82 are close to the surfaces of the lipid bilayer membrane for wild-type KCNE3 and KCNE3 containing interaction-impairing mutations. These results agree with earlier KCNE3 biophysical studies. The results of these MD simulations will provide complementary data to the experimental outcomes of KCNE3 to help understand its conformational dynamic properties in a more native lipid bilayer environment. 

Designing a surface that can disinfect itself can reduce labor-intensive cleanings and harmful waste, and mitigate spread of surface borne diseases. Additionally, since COVID-19 is an airborne pathogen, surface modification of masks and filters could assist with infection control. Styrene-maleic acid (SMA) copolymers and their derivatives were shown to have lipid-bilayer disrupting properties, making them candidates as anti-viral materials. A series of network polymers with styrene-maleic acid-based polymers and control over polymer chain-length and composition were synthesized. All the polymers formed mechanically robust structures, with tunable Young's moduli on the order of MPa, and tunable swelling capability in water. The SMA-based bulk materials, containing a zwitterionic polar unit, showed excellent lipid disrupting properties, being up to 2 times more efficient than a 10% Triton solution. The highest performance was observed for materials with lower crosslink densities or shorter chain-lengths, with lipid disruption capability correlating with swelling ratio. Additionally, the material can capture the spike protein of SARS-CoV-2, with up to 90% efficiency. Both the lipid disrupting and spike protein capture ability could be repeated for multiple cycles. Finally, the materials are shown to modify various porous and non-porous substrates including surgical and KN95 masks. Functional network modified masks had up to 6 times higher bilayer disruption ability than the unmodified masks without inhibiting airflow.