PNNL

Abstract

Classical molecular dynamics simulations of A-B+ LPS membrane model of Pseudomonas aeruginosa were carried out for 12+ ns. The B-band presents a remarkable flexibility remaining fully solvated and does not interact with the sugar units from the LPS core surface residues, in agreement atomic force microscopy experiments. Comparison with previous simulations of the rough LPS membrane suggests that the presence of the B-band promotes membrane expansion. In addition, this O-antigen chain dramatically alters the electrostatic potential and surface charge of the LPS membrane. This is illustrated by the resulting electrostatic surface potential. Comparison with the same property in rough LPS aids to explain the increased ability of B-band expressing microorganisms to adhere to cell surfaces and the necessity of these organisms to loose the O side chain for the development of acute infections.