Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature
The stochastic protrusion of hydrophobic lipid tails into solution, a subclass of hydrophobic membrane defects, has recently been shown to be a critical step in a number of biological processes like membrane fusion. Understanding the factors that govern the appearance of lipid tail protrusions is cr...
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| Format: | Article |
| Language: | en_US |
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Elsevier
2017
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| Online Access: | http://hdl.handle.net/1721.1/109406 https://orcid.org/0000-0002-8205-9158 https://orcid.org/0000-0001-5554-1283 |
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| author | Tahir, Mukarram A Van Lehn, Reid C Choi, Shinhyun Alexander-Katz, Alfredo |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Tahir, Mukarram A Van Lehn, Reid C Choi, Shinhyun Alexander-Katz, Alfredo |
| author_sort | Tahir, Mukarram A |
| collection | MIT |
| description | The stochastic protrusion of hydrophobic lipid tails into solution, a subclass of hydrophobic membrane defects, has recently been shown to be a critical step in a number of biological processes like membrane fusion. Understanding the factors that govern the appearance of lipid tail protrusions is critical for identifying membrane features that affect the rate of fusion or other processes that depend on contact with solvent-exposed lipid tails. In this work, we utilize atomistic molecular dynamics simulations to characterize the likelihood of tail protrusions in phosphotidylcholine lipid bilayers of varying composition, curvature, and hydration. We distinguish two protrusion modes corresponding to atoms near the end of the lipid tail or near the glycerol group. Through potential of mean force calculations, we demonstrate that the thermodynamic cost for inducing a protrusion depends on tail saturation but is insensitive to other bilayer structural properties or hydration above a threshold value. Similarly, highly curved vesicles or micelles increase both the overall frequency of lipid tail protrusions as well as the preference for splay protrusions, both of which play an important role in driving membrane fusion. In multi-component bilayers, however, the incidence of protrusion events does not clearly depend on the mismatch between tail length or tail saturation of the constituent lipids. Together, these results provide significant physical insight into how system components might affect the appearance of protrusions in biological membranes, and help explain the roles of composition or curvature-modifying proteins in membrane fusion. |
| first_indexed | 2024-09-23T16:28:02Z |
| format | Article |
| id | mit-1721.1/109406 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:28:02Z |
| publishDate | 2017 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/1094062022-10-02T08:06:04Z Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature Tahir, Mukarram A Van Lehn, Reid C Choi, Shinhyun Alexander-Katz, Alfredo Massachusetts Institute of Technology. Department of Materials Science and Engineering Tahir, Mukarram A Van Lehn, Reid C Choi, Shinhyun Alexander-Katz, Alfredo The stochastic protrusion of hydrophobic lipid tails into solution, a subclass of hydrophobic membrane defects, has recently been shown to be a critical step in a number of biological processes like membrane fusion. Understanding the factors that govern the appearance of lipid tail protrusions is critical for identifying membrane features that affect the rate of fusion or other processes that depend on contact with solvent-exposed lipid tails. In this work, we utilize atomistic molecular dynamics simulations to characterize the likelihood of tail protrusions in phosphotidylcholine lipid bilayers of varying composition, curvature, and hydration. We distinguish two protrusion modes corresponding to atoms near the end of the lipid tail or near the glycerol group. Through potential of mean force calculations, we demonstrate that the thermodynamic cost for inducing a protrusion depends on tail saturation but is insensitive to other bilayer structural properties or hydration above a threshold value. Similarly, highly curved vesicles or micelles increase both the overall frequency of lipid tail protrusions as well as the preference for splay protrusions, both of which play an important role in driving membrane fusion. In multi-component bilayers, however, the incidence of protrusion events does not clearly depend on the mismatch between tail length or tail saturation of the constituent lipids. Together, these results provide significant physical insight into how system components might affect the appearance of protrusions in biological membranes, and help explain the roles of composition or curvature-modifying proteins in membrane fusion. National Science Foundation (U.S.). MRSEC Program (award number DMR-0819762) National Science Foundation (U.S.). Faculty Early Career Development Program (Award No. DMR-1054671) United States. Department of Energy. Computational Science Graduate Fellowship Program (grant number DE-FG02-97ER25308) National Science Foundation (U.S.) (grant number OCI-1053575) 2017-05-30T13:46:51Z 2017-05-30T13:46:51Z 2016-01 2016-01 Article http://purl.org/eprint/type/JournalArticle 00052736 http://hdl.handle.net/1721.1/109406 Tahir, Mukarram A., Reid C. Van Lehn, S.H. Choi, and Alfredo Alexander-Katz. “Solvent-Exposed Lipid Tail Protrusions Depend on Lipid Membrane Composition and Curvature.” Biochimica et Biophysica Acta (BBA) - Biomembranes 1858, no. 6 (June 2016): 1207–1215. https://orcid.org/0000-0002-8205-9158 https://orcid.org/0000-0001-5554-1283 en_US http://dx.doi.org/10.1016/j.bbamem.2016.01.026 Biochimica et Biophysica Acta (BBA) - Biomembranes Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier Prof. Alexander-Katz via Angie Locknar |
| spellingShingle | Tahir, Mukarram A Van Lehn, Reid C Choi, Shinhyun Alexander-Katz, Alfredo Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title | Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title_full | Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title_fullStr | Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title_full_unstemmed | Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title_short | Solvent-exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| title_sort | solvent exposed lipid tail protrusions depend on lipid membrane composition and curvature |
| url | http://hdl.handle.net/1721.1/109406 https://orcid.org/0000-0002-8205-9158 https://orcid.org/0000-0001-5554-1283 |
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