Head group and interphasial hydration n some head group modifed analogues of dimyristoylphosphatidylethanolamine : A DSC and FTIR spectroscopy study.

RUTPHEN LEWIS; MARIA FRIAS; JOHN SILVIUS; RONALD MC ELHANEY

Boston, MS USA

Congreso; 53 Annual meeting Biophysical Society; 2009

Biophyscal Society

Headgroup and Interfacial Hydration in Some Headgroup-Modified Analogues of Dimyristoylphosphatidylethanolamine: A DSC and FTIR Spectroscopic Study Author Block Ruthven N. Lewis1, Maria Frias2, John R. Silvius3, Ronald N. McElhaney1. N. McElhaney1. N. McElhaney1. Ruthven N. Lewis1, Maria Frias2, John R. Silvius3, Ronald N. McElhaney1.1. 1University of Alberta, Edmonton, AB, Canada, 2University of Buenos Aires, Buenos Aires, Argentina, 3McGill University, Montreal, QC, Canada. Aires, Buenos Aires, Argentina, 3McGill University, Montreal, QC, Canada. Aires, Buenos Aires, Argentina, 3McGill University, Montreal, QC, Canada. University of Alberta, Edmonton, AB, Canada, 2University of Buenos Aires, Buenos Aires, Argentina, 3McGill University, Montreal, QC, Canada.3McGill University, Montreal, QC, Canada. Abstract: The thermotropic phase behavior and organization bilayers composed of dimyristoyl phosphatidylethanolamine and some of its headgroup-modified analogues were investigated by differential scanning calorimetry and by Page 1 of 3 Oasis, The Online Abstract Submission System 10/6/2008 http://www.abstractsonline.com/submit/submitSummary.asp?CKey=%7B922BD327%2D4... fourier-transform infrared spectroscopy. As expected, chemical modification of the lipid headgroup resulted in changes in the gel/liquidcrystalline phase transition temperatures of the analogues that were positively correlated with the capacity for inter headgroup hydrogenbonding to the phosphate moiety, and negatively correlated with the size of the headgroup substituent. However, such changes also drastically altered the nature of the lamellar crystalline phases formed by these compounds as well as the lateral packing interactions between the hydrocarbon chains. Moreover, although the chemical modifications of the polar headgroup did not alter the net charge of the lipid headgroup, they did nevertheless, markedly alter the susceptibility of these membranes to penetration by interfacially active molecules such as antimicrobial peptides. Our studies suggest that many of the effects of the chemical modification of the lipid headgroup can be rationalized in terms of their effects on the hydration of, and hydrogen-bonding interactions in the polar/polar interfacial regions of the lipid bilayer. : Author Disclosure Information: R.