This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.108.133736v1 95/5/2318    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Sun, Y. Articles by Huang, H. W. PubMed PubMed Citation Articles by Sun, Y. Articles by Huang, H. W.

The Bound States of Amphipathic Drugs in Lipid Bilayers: Study of Curcumin

Yen Sun ^*, Chang-Chun Lee ^*, Wei-Chin Hung , Fang-Yu Chen , Ming-Tao Lee  and Huey W. Huang ^*

^* Department of Physics and Astronomy, Rice University, Houston, Texas 77251; Department of Physics, Chinese Military Academy, Fengshan, Kaohsiung 83055, Taiwan; Department of Physics, National Central University, Chung-Li 32054, Taiwan; and National Synchrotron Radiation Research Center, Hsinchu, 30076 Taiwan

Correspondence: Address reprint request to Dr. Huey W. Huang, Dept. of Physics and Astronomy, Rice University, Houston, TX 77251-1892. Tel.: 713-348-4899; Fax: 713-348-4150; E-mail: hwhuang{at}rice.edu.

Drug-membrane interactions are well known but poorly understood. Here we describe dual measurements of membrane thickness change and membrane area change due to the binding of the amphipathic drug curcumin. The combined results allowed us to analyze the binding states of a drug to lipid bilayers, one on the water-membrane interface and another in the hydrocarbon region of the bilayer. The transition between the two states is strongly affected by the elastic energy of membrane thinning (or, equivalently, area stretching) caused by interfacial binding. The data are well described by a two-state model including this elastic energy. The binding of curcumin follows a common pattern of amphipathic peptides binding to membranes, suggesting that the binding states of curcumin are typical for amphipathic drugs.