Biomimetic Supported Lipid Bilayers with High Cholesterol Content Formed by α-helical Peptide-induced Vesicle Fusion

Published

May 24, 2012

Author(s)

Gregory J. Hardy, Rahul Nayak, S. Munir Alam, Joseph G. Shapter, Frank N. Heinrich, Stefan Zauscher

Abstract

In this study, we present a technique to create a complex, high cholesterol-containing SLB using α-helical (AH) peptide-induced vesicle fusion. Vesicles consisting of POPC: POPE: POPS: SM: Chol (9.35: 19.25: 8.25: 18.15: 45.00) were used to form a SLB that models the native composition of the human immunodeficiency virus-1 (HIV-1) lipid envelope. In the absence of AH peptides, these biomimetic vesicles fail to form a complete SLB. We verified and characterized AH peptide-induced vesicle fusion by quartz crystal microbalance with dissipation monitoring, neutron reflectivity, and atomic force microscopy. Successful SLB formation entailed a characteristic frequency shift of -35.4± 2.0 Hz and a change in dissipation energy of 1.91 ± 0.52 x 10^-6. Neutron reflectivity measurements determined the SLB thickness to be 49.9 ^+1.9_-1.5 A, and showed the SLB to be 100^+0.0_-0.1% complete and void of residual AH peptide after washing. Atomic force microscopy imaging confirmed complete SLB formation and revealed three distinct domains with no visible defects. This vesicle fusion technique gives researchers access to a broad range of SLB compositions and thus the ability to better recapitulate native cellular membranes.

Citation

Journal of Materials Chemistry

Pub Type

Journals

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Keywords

atomic force microscopy, neutron reflectometry, membrane model systems, vesicle fusion, HIV

Citation

Hardy, G. , Nayak, R. , Munir Alam, S. , Shapter, J. , Heinrich, F. and Zauscher, S. (2012), Biomimetic Supported Lipid Bilayers with High Cholesterol Content Formed by α-helical Peptide-induced Vesicle Fusion, Journal of Materials Chemistry, [online], https://doi.org/10.1039/c2jm32016a (Accessed May 14, 2024)