Bb. Bonev et Mr. Morrow, EFFECT OF PRESSURE ON THE DIMYRISTOYLPHOSPHATIDYLCHOLINE BILAYER MAINTRANSITION, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 55(5), 1997, pp. 5825-5833
Deuterium nuclear magnetic resonance was used to study the effect of p
ressure on the liquid crystal to gel phase transition in multilamellar
vesicles of chain perdeuterated dimyristoylphosphatidylcholine (DMPC-
d(54)). The first spectral moment (M-1), which is proportional to the
mean orientational order parameter for the DMPC-d(54) acyl chain, was
measured as a function of temperature at ambient pressure and at 160 M
Pa and as a function of pressure at 25 degrees C, 35 degrees C, and 45
degrees C. Application of hydrostatic pressure was found to increase
the magnitude of the jump in M-1 at the transition and to reduce the s
ensitivity of M-1 to temperature just above the transition. These obse
rvations suggest that the separation between the observed first-order
transition and the critical point for phospholipid bilayers increases
with increasing pressure.