Understanding the interfacial structure of aqueous phospholipid monolayer films via external reflection FT-IR spectroscopy

Academic Article

Abstract

  • Monolayer films of dimyristoyl-phosphatidic-acid (DMPA) at neutral and basic pH exhibit first-order phase transitions in their pressure-area curves. In situ external reflection FT-IR studies in the CH2 stretching bands over this phase transition region exhibit a ˜-6 cm-1 shift similar to that observed in previous studies of dipalmitoyl-phosphotidylcholine (DPPC)1. The acid form of DMPA at pH 3.0 does not exhibit the first order phase transition, but a ˜-1 cm-1 frequency shift is observed in the liquid condensed phase and is also present in the neutral pH form. A solid-solid phase transition is proposed. Examination of the polar headgroup region (1300-960 cm-1) for acidic, neutral, and basic forms of DMPA give characteristic bands of each protonation state of PO3. © 1989 SPIE.
  • Authors

    Published In

    Digital Object Identifier (doi)

    Pubmed Id

  • 23393050
  • Author List

  • Mitchell ML; Dluhy RA
  • Start Page

  • 255
  • End Page

  • 256
  • Volume

  • 1145