CONFIGURATION OF CARBONYL GROUPS AT THE Lb ´, Pb´ AND La PHASES OF LIPID INTERPHASES

FRIAS, M DE LOS ANGELES; DIAZ, SONIA; DISALVO, E ANIBAL

Montevideo, Uruguay

Congreso; 34 Meeting Argentine Biophysical Society; 2007

Sociedad Argentina de Biofisica

  The increasing temperature in phosphatidylcholines promotes a pretransition from the Lb to the Pb ripple phase. At the main transition, the Pb phase transforms into the La phase. Each of these phases is characterized by the level of hydration. In the ripple phase, in addition to the increase in the hydration, a defective packing has been detected as a consequence of the coexistence of gel and fluid domains.             In this work, we show that the different extents of hydration of the different  phase states correspond to different distribution between the hydrated and non hydrated population of carbonyls as deduced from the FTIR analysis. In addition, compounds that may avoid the pretransition produces a shift in the carbonyl population congruent with the disappearance of the ripples phase.