Alamethicin-lipid interaction studied by energy dispersive X-ray diffraction

作者：Domenici F; Panichelli D; Castellano A Congiu^*

来源：Colloids and Surfaces B: Biointerfaces , 2009, 69(2): 216-220.

DOI：10.1016/j.colsurfb.2008.11.029

• X-ray diffraction
• Alamethicin
• Lipid membrane

A detailed knowledge of the interaction between bacterial membranes and antibiotics provides important information to prevent high levels of antibiotic resistance exhibited by pathogenic strains. We investigated by energy dispersive X-ray diffraction (EDXD) the structure ordering of dioleoyl-phosphatidylcholine (DOPC) lipid interacting with antimicrobial peptide alamethicin, varying the lipid/peptide (L/P) molar ratio under two different hydration levels.
In conditions of full hydration (100%) we found that the bilayer thickness is constant between L/P = 20 and L/P = 80 indicating that in this range, the system has reached the threshold value for the channel formation, while at the relative hydration of 45% a linear decrease of the bilayer thickness as function of L/P was revealed. The kinetic Study of the complex alamethicin-DOPC at different L/P values, shows that the Bragg peak energy variation versus the hydration time has a biexponential behavior characterized by two different time constants.

• 出版日期2009-3-1