Abstract
Methanol is a common solubilizing agent used to study transmembrane proteins/peptides in biological and synthetic membranes. Using small angle neutron scattering and a strategic contrast-matching scheme, we show that methanol has a major impact on lipid dynamics. Under increasing methanol concentrations, isotopically distinct 1,2-dimyristoyl-sn-glycero-3-phosphocholine large unilamellar vesicle populations exhibit increased mixing. Specifically, 1,2-dimyristoyl-sn-glycero-3-phosphocholine transfer and flip-flop kinetics display linear and exponential rate enhancements, respectively. Ultimately, methanol is capable of influencing the structure-function relationship associated with bilayer composition (e.g., lipid asymmetry). The use of methanol as a carrier solvent, despite better simulating some biological conditions (e.g., antimicrobial attack), can help misconstrue lipid scrambling as the action of proteins or peptides, when in actuality it is a combination of solvent and biological agent. As bilayer compositional stability is crucial to cell survival and protein reconstitution, these results highlight the importance of methanol, and solvents in general, in biomembrane and proteolipid studies.
Original language | English |
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Pages (from-to) | 755-759 |
Number of pages | 5 |
Journal | Biophysical Journal |
Volume | 116 |
Issue number | 5 |
DOIs | |
State | Published - Mar 5 2019 |
Funding
We acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce in providing the neutron research facilities used in this work. Access to the VSANS instrument was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Science Foundation and the National Institute of Standards and Technology under Agreement DMR-1508249. A portion of this research at Oak Ridge National Laboratory's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. M.D. and M.H.L.N. are both supported by Ontario Graduate Scholarships. D.M. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada [funding reference number 2018-04841]. We acknowledge the support of the National Institute of Standards and Technology , U.S. Department of Commerce in providing the neutron research facilities used in this work. Access to the VSANS instrument was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Science Foundation and the National Institute of Standards and Technology under Agreement DMR-1508249. A portion of this research at Oak Ridge National Laboratory’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division , Office of Basic Energy Sciences , U.S. Department of Energy . M.D. and M.H.L.N. are both supported by Ontario Graduate Scholarships . D.M. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada [funding reference number 2018-04841 ].