IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effect of thujone and dihydrocarvone on phospholipid monolayer
Autor/es:
MARIANI, ME; SANCHEZ BORZONE, M; GARCIA, DA
Lugar:
Salto
Reunión:
Simposio; LACBi2015 - LATIN AMERICAN CROSSTALK IN BIOPHYSICS; 2015
Institución organizadora:
LAFeBS/SAB/ SBF.uy
Resumen:
The GABAA receptor (GABA-R) is the main inhibitoryreceptor of the Central Nervous System and is an instrinsic protein whichactivity may be affected by physical changes in membrane. It possesses bindingsites for drugs other than the neurotransmitter GABA, including the convulsantpicrotoxine which behave as allosteric modulator or channel blocker and showedto be especially relevant since it constitutes the action site of widely usedneurotoxic organochlorine pesticides. Moreover, many compounds that regulateGABA-R function are noticeably lipophilic, which can interact with membranelipids and cause various changes in their physical properties (molecular area,surface tension, surface potential, etc) and, consequently, in membrane dynamicproperties (fluidity, viscosity, etc) modulating receptor macromolecules.Taking into account that both cyclic ketones studied in the present work,thujone (the reference compound) and dihydrocarvone (which shows to be verysimilar structurally), are highly lipophilic, we focus on the membraneinteraction study using phospholipidic monolayers of dpPC.  Surface pressure versus area isothermsmeasured in the presence or absence of 20, 250 and 500 μM ketones in thesubphase showed the compounds are able to expand the LE phase of thephospholipidic film in a concentration dependent manner, due to theirincorporation into the monolayer favored by less-packed structures. Thetransition phase observed in dpPC disappeared in the presence of these cyclicketones. Compressibility modulus determination shows that all ketones modifythe membrane elasticity. Furthermore, these compounds could easily penetrate onthe membrane according to their ability to incorporate into the monomolecular film atdifferent molecular pressures showing a πcutoff of 22 and 27 mN/mfor dihydrocarvone and thujone respectively.