Original scientific paper

A DSC and Raman Study of the Interaction between Tricresyl Phosphates (TCP) and Phospholipid Liposomes

Sergio Bonora
Andrea Trinchero
Armida Torreggiani
Maurizio Tamba

Abstract

This paper reports on the DSC and Raman measurements of hydrated multilamellar dimyristoylphosphatidylcholine
(DMPC) and dimyristoylphosphatidylethanolamine (DMPE) liposomes
in the presence of raw tricresyl phosphates (TCP) and pure tri-o-cresyl phosphate (TOCP).
The results on TCP/DMPC and TOCP/DMPC liposomes showed no significant differences. Both
the Tm decrease and DT1/2 increase, obtained by increasing the relative amount of TCP with
respect to liposomes, suggested that the hydrophobic core is strongly affected by the presence
of TCP molecules, whose deep penetration into the bilayer is prevented by the polar interactions
between the P=O group of the TCP molecules and the polar head on DMPC. On the contrary,
the TCP/DMPE and TOCP/DMPE systems showed a phase segregation that takes place
in the presence of a very small amount of TCP, and occurs somewhat more easily in the presence
of TOCP than of raw TCP. Both TCP and TOCP molecules interact mainly with the outer
face of the bilayer and only secondly affect the hydrophobic core of membranes.

Keywords

phospholipids; tricresylphosphates; phase transition; DSC; Raman spectroscopy

Hrčak ID:

12828

URI

https://hrcak.srce.hr/12828

Publication date:

11.3.2007.

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