Influence of Cholesterol on the Phase Transition of Lipid Bilayers: A Temperature-Controlled Force Spectroscopy Study

Given their amphiphilic nature and chemical structure, phospholipids exhibit a strong thermotropic and lyotropic phase behaviour in an aqueous environment. Around the phase transition temperature, phospholipids transform from a gel-like state to a fluid crystalline structure. In this transition, many key characteristics of the lipid bilayers such as structure and thermal properties alter. In this study, we employed atomistic simulation techniques to study the structure and underlying mechanisms of heat transfer in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers around the fluid–gel phase transformation. To investigate this phenomenon, we performed non-equilibrium molecular dynamics simulations for a range of different temperature gradients. The results show that the thermal properties of the DPPC bilayer are highly dependent on the temperature gradient. Higher temperature gradients cause an increase in the thermal conductivity of the DPPC lipid bilayer. We also found that the thermal conductivity of DPPC is lowest at the transition temperature whereby one lipid leaflet is in the gel phase and the other is in the liquid crystalline phase. This is essentially related to a growth in thermal resistance between the two leaflets of lipid at the transition temperature. These results provide significant new insights into developing new thermal insulation for engineering applications.

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The Image-Based Observation of the LβI-to-Lβ‘ Phase Transition in Solid-Supported Lipid Bilayers

Langmuir ◽

10.1021/la010295+ ◽

2001 ◽

Vol 17 (16) ◽

pp. 5121-5124 ◽

Cited By ~ 13

Author(s):

Robert L. McClain ◽

J. J. Breen

Keyword(s):

Phase Transition ◽

Lipid Bilayers ◽

Supported Lipid Bilayers

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Force spectroscopy based on temperature controlled atomic force microscope head using piezoresistive cantilevers

Review of Scientific Instruments ◽

10.1063/1.1884191 ◽

2005 ◽

Vol 76 (4) ◽

pp. 043701 ◽

Cited By ~ 8

Author(s):

I. Muševič ◽

K. Kočevar ◽

U. Kržič ◽

G. Carbone

Keyword(s):

Atomic Force Microscope ◽

Force Spectroscopy ◽

Atomic Force ◽

Piezoresistive Cantilevers ◽

Temperature Controlled

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Analysis of Phase Transition Dynamics Under Temperature Controlled Conditions

ECS Meeting Abstracts ◽

10.1149/ma2014-04/4/683 ◽

2014 ◽

Keyword(s):

Phase Transition ◽

Transition Dynamics ◽

Controlled Conditions ◽

Temperature Controlled

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Unique Phase Transition of Exogenous Fusion Elastin-like Polypeptides in the Solution Containing Polyethylene Glycol

International Journal of Molecular Sciences ◽

10.3390/ijms20143560 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3560

Author(s):

Zhongqi Ge ◽

Ziyang Xiong ◽

Dandan Zhang ◽

Xialan Li ◽

Guangya Zhang

Keyword(s):

Phase Transition ◽

Polyethylene Glycol ◽

Transition Temperature ◽

Fluorescence Spectroscopy ◽

Fusion Protein ◽

Molecular Mechanism ◽

Phase Transition Temperature ◽

Temperature Controlled

Elastin-Like polypeptides (ELPs), as well-known temperature-controlled bio-macromolecules, are widely used. However, little is known about the interactions between ELPs and macromolecules, which is an important yet neglected problem. Here, the phase transition characteristics of an ELPs-SpyCatcher fusion protein (E-C) in the presence of polyethylene glycol (PEG) in single salts (Na2CO3, Na2SO4, NaCl) solutions were investigated using a UV spectrophotometer, DLC, and fluorescence spectroscopy, and we got some interesting results. The phases transition of E-C occurred at a concentration lower than 0.5 mol/L Na2CO3/PEG2000, while in single Na2CO3 (<0.5 mol/L), the phase transition of E-C did not occur. In the Na2CO3/PEG solution, we observed a unique two-step phase transition of E-C when the Na2CO3 concentration was 0.5 mol/L and PEG2000 concentration was less than 0.15 g/mL, respectively. In the Na2CO3/PEG2000 solution, the phase-transition temperature of E-C decreased with the increase of PEG concentration, but increased in the Na2SO4/PEG2000 solution, while it remained unchanged in the NaCl/PEG2000 solution. However, the phase-transition temperature of the linear ELPs40 decreased under the same salts/PEG2000 solutions. We also addressed the possible molecular mechanism of the interesting results. In contrast to the current well-understood salts-ELPs interactions, this work provides some new insights into the interaction between the PEG-salts-ELPs in solution.

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