Mechanical Pull On A Guest Molecule By A Photoresponsive Lipid Bilayer

Autor: Claus Helix Nielsen, Salim Abdali, Peter Tidemand-Lichtenberg, Bert Poolman, Johanna M. Kuiper, Jens A. Lundbæk, Jan B. F. N. Engberts
Rok vydání: 2009
Předmět:
Zdroj: ResearcherID
ISSN: 0006-3495
DOI: 10.1016/j.bpj.2008.12.681
Popis: One of the central challenges in nanotechnology is to develop tools for reversible, mechanical manipulation of non-covalently bound single molecules. Using the gramicidin (gA) channel, we demonstrate that light-induced changes in the mechanical properties of a photoresponsive lipid bilayer allow for optical control of the bilayer disjoining force on a non-covalently bound guest molecule. The gA channel is formed by trans-bilayer association of a monomer from each monolayer in a lipid bilayer. Channel formation in a bilayer where the thickness of the bilayer hydrophobic core exceeds the channel length, involves a local bilayer thinning to match the channel. The bilayer, in response to the deformation, exerts a disjoining force on the channel - the magnitude of which is determined by the bilayer mechanical properties. We studied gA channels in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC): di-(5-{[4-(4-butylphenyl)azo]phenoxy}pentyl (4-Azo-5P)/n-decane bilayers using single channel voltage clamp techniques. Upon exposure to UV light, the azobenzene moiety in the acyl chains of 4-Azo-5P undergoes a reversible trans-to-cis isomerization, known alter the physical properties of this lipid. By exposing gA channels in DOPC:4-Azo-5P bilayers to alternating visible or UV light, the bilayer disjoining force on the channel was altered such as to cause rapid, reversible changes in channel dissociation rate.
Databáze: OpenAIRE