Publication
Article Metrics
Citations
Online attention
The role of protein hydrophobicity in thionin–phospholipid interactions: a comparison of alpha 1 and alpha 2-purothionin adsorbed anionic phospholipid monolayers
Authors:
Luke
Clifton
(ISIS)
,
Michael
Sanders
(University of Reading, U.K.)
,
Christy
Kinane
(ISIS Pulsed Neutron and Muon Source)
,
Tom
Arnold
(Diamond Light Source)
,
Karen J.
Edler
(University of Reading)
,
Cameron
Neylon
(ISIS Spallation Neutron Source, Science and Technology Facilities Council)
,
Rebecca
Green
(University of Reading)
,
Richard
Frazier
(University of Reading)
Co-authored by industrial partner:
No
Type:
Journal Paper
Journal:
Physical Chemistry Chemical Physics
, VOL 14 (39)
, PAGES 13569-13579
State:
Published (Approved)
Published:
August 2012
Diamond Proposal Number(s):
6306
Abstract: The plant defence proteins ?1- and ?2-purothionin (Pth) are type 1 thionins from common wheat (Triticum aestivum). These highly homologous proteins possess characteristics common amongst antimicrobial peptides and proteins, that is, cationic charge, amphiphilicity and hydrophobicity. Both ?1- and ?2-Pth possess the same net charge, but differ in relative hydrophobicity as determined by C18 reversed phase HPLC. Brewster angle microscopy, X-ray and neutron reflectometry, external reflection FTIR and associated surface pressure measurements demonstrated that ?1 and ?2-Pth interact strongly with condensed phase 1,2-dipalmitoyl-sn-glycero-3-phospho-(1?-rac-glycerol) (DPPG) monolayers at the air/liquid interface. Both thionins disrupted the in-plane structure of the anionic phospholipid monolayers, removing lipid during this process and both penetrated the lipid monolayer in addition to adsorbing as a single protein layer to the lipid head-group. However, analysis of the interfacial structures revealed that the ?2-Pth showed faster disruption of the lipid film and removed more phospholipid (12%) from the interface than ?1-Pth. Correlating the protein properties and lipid binding activity suggests that hydrophobicity plays a key role in the membrane lipid removal activity of thionins.
Journal Keywords: Plant Defence Proteins; Triticum Aestivum; Cationic Charge; Amphiphilicity; Hydrophobicity;
Subject Areas:
Biology and Bio-materials
Instruments:
I07-Surface & interface diffraction