title: Scanning calorimetry reveals a new phase transition in L-alpha-dipalmitoylphosphatidylcholine.
abstract: We report a new phase transition in fully hydrated dispersions of dipalmitoylphosphatidylcholine (DPPC). This new transition, called the sub-subtransition, exhibits a transition enthalpy of 0.25 kcal/mol with a Tm at 6.8 degrees C. Unlike the subtransition, no extended low temperature incubation is required to observe the sub-subtransition. This new sub-subgel (SGII) phase may be a precursor to the subgel (SGI) phase, and this discovery is discussed in relation to the current knowledge regarding the polymorphic gel phases of both ester- and ether-linked lipids with identical acyl chains.
authors: Department of Biochemistry, University of Virginia School of Medicine, Charlottesville 22908.
authors: J L
authors: JL
authors: Slater
authors: C
authors: C
authors: Huang
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine; D002152:Calorimetry, Differential Scanning; D008051:Lipid Bilayers; D008954:Models, Biological; D008968:Molecular Conformation
chemical_list: D008051:Lipid Bilayers; D015060:1,2-Dipalmitoylphosphatidylcholine