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

Autor: Campbell C; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Faleel FDM; Department of Chemistry and Biochemistry, Miami University, Oxford, OH, United States of America., Scheyer MW; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Haralu S; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Williams PL; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Carbo WD; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Wilson-Taylor AS; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Patel NH; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America., Sanders CR; Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN, United States of America., Lorigan GA; Department of Chemistry and Biochemistry, Miami University, Oxford, OH, United States of America., Sahu ID; Natural Science Division, Campbellsville University, Campbellsville, KY, United States of America; Department of Chemistry and Biochemistry, Miami University, Oxford, OH, United States of America. Electronic address: idsahu@campbellsville.edu.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Biomembranes [Biochim Biophys Acta Biomembr] 2022 Oct 01; Vol. 1864 (10), pp. 183974. Date of Electronic Publication: 2022 Jun 15.
DOI: 10.1016/j.bbamem.2022.183974
Abstrakt: 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.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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