TY - JOUR
T1 - Interaction of an amphipathic peptide with phosphatidycholine/ phosphatidylethanolamine mixed membranes
AU - Shintou, Keisuke
AU - Nakano, Minoru
AU - Kamo, Tomoari
AU - Kuroda, Yoshihiro
AU - Handa, Tetsurou
N1 - Funding Information:
This study was supported in part by Grants-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (No. 17390011 and 17655005), SHISEIDO Grant for Science Research, and by the program for Promotion of Fundamental Studies in Health Science of the National Institute of Biomedical Innovation.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - The effect of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) in mixed membranes with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) on interaction with a class A amphipathic peptide, Ac-DWLKAFYDKVAEKLKEAF-NH 2 (Ac-18A-NH2), was investigated. The fluorescence lifetime of 2-(9-anthroyloxy)stearic acid and 2H NMR spectra were used to evaluate the penetration of water molecules into the membrane interface and the order of lipid acyl chains, respectively. The results demonstrated that DOPE in the mixed membranes decreased the fluorescence lifetime and increased the acyl-chain order, and that Ac-18A-NH2 affected them more for membranes with higher DOPE fractions. The partition coefficient (Kp) of the peptide to the mixed membranes was increased with the increase in the DOPE mole fractions. From the temperature dependence of the Kp values, the binding of Ac-18A-NH2 to POPC/DOPE mixed membranes was found to be entropy-driven. The formation of an α-helix at the membrane's surface is supposed to induce positive curvature strain, which decreases the headgroup hydration and acylchain order of lipids. Thus, the binding of Ac-18A-NH2 to membranes is entropically more favorable at higher DOPE fractions since the peptide's insertion into the membrane can decrease the order parameter and unfavorable headgroup hydration, which explains the enhanced peptide binding.
AB - The effect of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) in mixed membranes with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) on interaction with a class A amphipathic peptide, Ac-DWLKAFYDKVAEKLKEAF-NH 2 (Ac-18A-NH2), was investigated. The fluorescence lifetime of 2-(9-anthroyloxy)stearic acid and 2H NMR spectra were used to evaluate the penetration of water molecules into the membrane interface and the order of lipid acyl chains, respectively. The results demonstrated that DOPE in the mixed membranes decreased the fluorescence lifetime and increased the acyl-chain order, and that Ac-18A-NH2 affected them more for membranes with higher DOPE fractions. The partition coefficient (Kp) of the peptide to the mixed membranes was increased with the increase in the DOPE mole fractions. From the temperature dependence of the Kp values, the binding of Ac-18A-NH2 to POPC/DOPE mixed membranes was found to be entropy-driven. The formation of an α-helix at the membrane's surface is supposed to induce positive curvature strain, which decreases the headgroup hydration and acylchain order of lipids. Thus, the binding of Ac-18A-NH2 to membranes is entropically more favorable at higher DOPE fractions since the peptide's insertion into the membrane can decrease the order parameter and unfavorable headgroup hydration, which explains the enhanced peptide binding.
UR - http://www.scopus.com/inward/record.url?scp=36849027174&partnerID=8YFLogxK
U2 - 10.1529/biophysj.107.108399
DO - 10.1529/biophysj.107.108399
M3 - 学術論文
C2 - 17704174
AN - SCOPUS:36849027174
SN - 0006-3495
VL - 93
SP - 3900
EP - 3906
JO - Biophysical Journal
JF - Biophysical Journal
IS - 11
ER -