Melatonin strongly interacts with zwitterionic model membranes - evidence from Fourier transform infrared spectroscopy and differential scanning calorimetry

Severcan F., Sahin I., Kazanci N.

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, vol.1668, no.2, pp.215-222, 2005 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 1668 Issue: 2
  • Publication Date: 2005
  • Doi Number: 10.1016/j.bbamem.2004.12.009
  • Journal Name: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.215-222
  • Keywords: melatonin, dipalmitoyl phosphatidylcholine, membrane, liposome, Fourier transform infrared, differential scanning calorimetry, phase separation, ALPHA-TOCOPHEROL, OXIDATIVE DAMAGE, PHASE-BEHAVIOR, FLUIDITY, OXYGEN, ORDER, ASCORBATE, ACETATE
  • Middle East Technical University Affiliated: No

Abstract

Interactions of melatonin with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes (MLVs) were investigated as a function of temperature and melatonin concentration (1-30 mol%) by using two noninvasive techniques, namely Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The investigation of the C-H, C=O, and PO2- antisymmetric double stretching modes in FTIR spectra and DSC studies reveal that melatonin changes the physical properties of the DPPC bilayers by decreasing the main phase transition temperature, abolishing the pretransition, ordering the system in the gel phase, and increasing the dynamics of the system both in the gel and liquid crystalline phases. It also causes significant decrease in the wavenumber for the C=O stretching and PO2- antisymmetric double bond stretching bands, which indicates strong hydrogen bonding The results imply that melatonin locates in the interfacial region of the membrane. Furthermore, in the DSC curve, more than one signal is observed at high melatonin concentrations (24 and 30 mol%), which indicates melatonin-induced phase separation in DPPC membranes. (C) 2005 Elsevier B.V. All rights reserved.