title: Membrane-thinning effect of curcumin.
abstract: Interaction of curcumin with lipid bilayers is not well understood. A recent experiment showed that curcumin significantly affected the single-channel lifetime of gramicidin in a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer without affecting its single-channel conductance. We performed two experiments to understand this result. By isothermal titration calorimetry, we measured the partition coefficient of curcumin binding to DOPC bilayers. By x-ray lamellar diffraction, we measured the thickness change of DOPC bilayers as a function of the curcumin/lipid ratio. A nonlinear membrane-thinning effect by curcumin was discovered. The gramicidin data were qualitatively interpreted by the combination of isothermal titration calorimetry and x-ray results. We show that not only does curcumin thin the lipid bilayer, it might also weaken its elasticity moduli. The result implies that curcumin may affect the function of membrane proteins by modifying the properties of the host membrane.
authors.affiliation: Department of Physics, Chinese Military Academy, Fengshan, Kaohsiung, 83055 Taiwan.
authors.forename: Wei-Chin
authors.initials: WC
authors.lastname: Hung
authors.forename: Fang-Yu
authors.initials: FY
authors.lastname: Chen
authors.forename: Chang-Chun
authors.initials: CC
authors.lastname: Lee
authors.forename: Yen
authors.initials: Y
authors.lastname: Sun
authors.forename: Ming-Tao
authors.initials: MT
authors.lastname: Lee
authors.forename: Huey W
authors.initials: HW
authors.lastname: Huang
mesh_terms: D003198:Computer Simulation; D003474:Curcumin / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010713:Phosphatidylcholines / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; C017251:1,2-oleoylphosphatidylcholine; D003474:Curcumin