Arbutin blocks defects in the ripple phase of DMPC bilayers by changing carbonyl organization.

FRIAS, M DE LOS ANGELES; NICASTRO, AL; CASADO, N.; GENNARO, A.M.; DIAZ, S.B.; DISALVO, E.A.

CHEMISTRY AND PHYSICS OF LIPIDS

Elsevier

Lugar: Amsterdam; Año: 2007 vol. 147 p. 22 - 29

0009-3084

The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV´s) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV´s are known to be in the ripple P(beta´) phase, than at 10 degrees C (L(beta´) flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV´s when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert. PMID: 17442288 [PubMed - indexed for MEDLINE]