Response of microbial membranes to butanol : interdigitation vs. disorder
| Autor: | Thomas Seviour, Atul N. Parikh, Alan E. Mark, Staffan Kjelleberg, Bo Liedberg, Hokyun Chin, Jingjing Guo, Yuguang Mu, Jamie Hinks, Cheng Zhou, Nam-Joon Cho, James C. S. Ho |
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| Přispěvatelé: | School of Materials Science and Engineering, School of Biological Sciences, School of Chemical and Biomedical Engineering, Singapore Centre for Environmental Life Sciences and Engineering, Centre for Biomimetic Sensor Science (CBSS) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Lipid Bilayers
Intercalation (chemistry) Phospholipid General Physics and Astronomy 02 engineering and technology Molecular Dynamics Simulation 010402 general chemistry 01 natural sciences Cell membrane chemistry.chemical_compound 1-Butanol Microbial Membranes Escherichia coli medicine Transition Temperature Physical and Theoretical Chemistry Lipid bilayer Unilamellar Liposomes Materials [Engineering] Phosphatidylethanolamines Bilayer Vesicle Butanol Cell Membrane Phosphatidylglycerols equipment and supplies 021001 nanoscience & nanotechnology 0104 chemical sciences carbohydrates (lipids) Membrane medicine.anatomical_structure chemistry Biophysics bacteria lipids (amino acids peptides and proteins) 0210 nano-technology |
| Popis: | Biobutanol production by fermentation is potentially a sustainable alternative to butanol production from fossil fuels. However, the toxicity of butanol to fermentative bacteria, resulting largely from cell membrane fluidization, limits production titers and is a major factor limiting the uptake of the technology. Here, studies were undertaken, in vitro and in silico, on the butanol effects on a representative bacterial (i.e. Escherichia coli) inner cell membrane. A critical butanol : lipid ratio for stability of 2 : 1 was observed, computationally, consistent with complete interdigitation. However, at this ratio the bilayer was ∼20% thicker than for full interdigitation. Furthermore, butanol intercalation induced acyl chain bending and increased disorder, measured as a 27% lateral diffusivity increase experimentally in a supported lipid bilayer. There was also a monophasic Tm reduction in butanol-treated large unilamellar vesicles. Both behaviours are inconsistent with an interdigitated gel. Butanol thus causes only partial interdigitation at physiological temperatures, due to butanol accumulating at the phospholipid headgroups. Acyl tail disordering (i.e. splaying and bending) fills the subsequent voids. Finally, butanol short-circuits the bilayer and creates a coupled system where interdigitated and splayed phospholipids coexist. These findings will inform the design of strategies targeting bilayer stability for increasing biobutanol production titers. Ministry of Education (MOE) Nanyang Technological University National Research Foundation (NRF) Accepted version The computational work for this article was performed on resources of the National Supercomputing Centre, Singapore (https://www.nscc.sg). This work was supported by the Ministry of Education, Singapore (MOE) Grants M4360005 and Tier 1 RG146/17. SCELSE is funded by Singapore’s Ministry of Education, National Research Federation, Nanyang Technological University (NTU), and National University of Singapore (NUS) and hosted by NTU in partnership with NUS. |
| Databáze: | OpenAIRE |
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