Raman spectroscopy study of the interaction of 3,5,3′-triiodo-L-thyronine with phosphatidylglycerol lipid bilayers

MARCELO, SOSA MORALES; ANA CAROLINA JUÁREZ; ALVAREZ, ROSA MARÍA S.

JOURNAL OF RAMAN SPECTROSCOPY

JOHN WILEY & SONS LTD

Lugar: LOndres; Año: 2015

0377-0486

A Raman spectroscopic study of anionic modelmembranes and their structural alterations exerted by a relatively small biomolecule,such as the hormone 3,5,3′-triiodo-L-thyronine (T3), is presented. Spectral differences between pure dipalmitoylphosphatidylglycerol(DPPG) multilamellar vesicles and DPPG?T3 mixture and between pure dilauroylphosphatidylglycerol (DLPG) and DLPG?T3 mixturewere evaluated in order to determine the response of lipid membranes in gel and liquid-crystalline phases to the hormone incorporation.Density functional theory (DFT) calculations support the band analysis of the complex 1150?1050cm1 Raman region. Geometryoptimizations and vibrational behaviors of a model charged molecule that mimics the phosphatidylglycerol lipid moiety insolvated statewere taken into account for the spectral interpretation of this specific region. The anionic nature of the lipid polar headplays an important role in the interaction with the hormone, as is evidenced by the C¼O and PO2 stretching bands. In addition, thedifferential penetration of T3 into the hydrophobic region of themembranes shows to be dependent on the lipid phase. The spectraldata were compared with those previously obtained for zwitterionic membranes.