Characteristics of Pyrene Phospholipid/γ-Cyclodextrin Complex
Characteristics of Pyrene Phospholipid/γ-Cyclodextrin Complex
复制标题
芘磷脂/γ-环糊精复合物的特性
DOI：
10.1016/s0006-3495(01)75804-3
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发表时间：
2001
影响因子：
3.4
通讯作者：
P. Somerharju
中科院分区：
文献类型：
--
作者：
K. Tanhuanpää;K. Cheng;K. Anttonen;J. Virtanen;P. Somerharju
最近，研究表明，γ-环糊精(γ-CDS)可以极大地加速疏水的芘标记的磷脂衍生物和其他荧光磷脂衍生物从囊泡到培养细胞的转移(Tanhuanpää和Somerharju，1999年)。为了更好地了解这一过程的特点，我们用各种物理方法研究了γ-CD与芘标记的磷脂酰胆碱(PYRPC)的相互作用。PC的一个或两个酰基链上都标记了芘部分(分别是单吡咯烷基和双吡咯烷基)，标记链的长度(S)从4到14个碳不等。荧光结合分析表明，随着酰基链长的增加，结合常数明显减小。对于短链物种，PYRPC/γ-CD的化学计量比为1：2，但当酰基链长超过8(二吡咯)碳或10(一吡咯)碳时变为1：3。DiPyr10PC/γ-CD络合物的形成活化能较高，为+92kJ/m ol，说明磷脂分子必须完全从双层中出来才能形成络合物。单分子吡咯烷酮从双层到γ-Cd络合物的转移自由能、热焓和转移熵接近于零。吸收光谱、傅里叶变换红外光谱、荧光光谱测量和寿命分析表明，芘部分存在于CD空腔内，并受到构象限制，特别是当标记的链较短时。吡咯环丙烷分子的酰基链似乎共用一个CD空穴，而不是占据不同的空穴。目前的数据提供了强有力的证据表明，γ-CD促进Py标记的磷脂的膜间转移的能力是基于水相中化学计量比络合物的形成。这些信息应该有助于设计比目前可用的更有效的脂质载体的CD衍生物。
Recently, it was demonstrated thatγ-cyclodextrins (γ-CDs) greatly accelerates transfer of hydrophobic pyrene-labeled and other fluorescent phospholipid derivatives from vesicles to cells in culture (Tanhuanpää and Somerharju, 1999). To understand better the characteristics of this process, we studied the interaction ofγ-CD with pyrene-labeled phosphatidylcholines (PyrPCs) using a variety of physical methods. Either one or both of the acyl chains of PC was labeled with a pyrene moiety (monoPyrPCs and diPyrPCs, respectively), and the length of the labeled chain(s) varied from 4 to 14 carbons. Fluorescent binding assays showed that the association constant decreases strongly with increasing acyl chain length. PyrPC/γ-CD stoichiometry was 1:2 for the shorter chain species, but changed to 1:3 when the acyl chain length exceeded 8 (diPyrPCs) or 10 (monoPyrPCs) carbons. The activation energy for the formation of diPyr10PC/γ-CD complex was high, i.e., +92 kJ/mol, indicating that the phospholipid molecule has to fully emerge from the bilayer before complex formation can take place. The free energy, enthalpy, and entropy of transfer of monoPyrPC from bilayer toγ-CD complex were close to zero. The absorption, Fourier transform infrared, and fluorescence spectral measurements and lifetime analysis indicated that the pyrene moiety lies inside the CD cavity and is conformationally restricted, particularly when the labeled chain is short. The acyl chains of a PyrPC molecule seem to share a CD cavity rather than occupy different ones. The present data provide strong evidence that the ability ofγ-CD to enhance intermembrane transfer of pyrene-labeled phospholipids is based on the formation of stoichiometric complexes in the aqueous phase. This information should help in designing CD derivatives that are more efficient lipid carriers then those available at present.
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DOI：
10.1016/0005-2760(85)90038-4
发表时间：
1985
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Massey,JB;Hickson-Bick,D;Via,DP;GottoJr,AM;Pownall,HJ
通讯作者：
Pownall,HJ
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DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
vanHelvoort,A;van'tHof,W;Ritsema,T;Sandra,A;vanMeer,G
通讯作者：
vanMeer,G
影响因子：
2.9
作者：
MCLEAN, LR;PHILLIPS, MC
通讯作者：
PHILLIPS, MC
DOI：
10.1016/0005-2760(84)90156-5
发表时间：
1984-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
MASSEY, JB;HICKSON, D;POWNALL, HJ
通讯作者：
POWNALL, HJ
影响因子：
6.5
作者：
A. E. Christian;M. Haynes;M. Phillips;G. Rothblat
通讯作者：
A. E. Christian;M. Haynes;M. Phillips;G. Rothblat