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Molecular Dynamics in Lipid Rafts by High-Sensitivity, High-Resolution NMR

通过高灵敏度、高分辨率 NMR 分析脂筏中的分子动力学

基本信息

批准号：
17550153
负责人：
OKAMURA Emiko
金额：
$ 1.79万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17550153/
关键词：
cholesterol lipid raft dynamics solution NMR aggregate biophysics diffusion NOESY 2次元NMR 自己組織化

项目摘要

Cholesterol is involved in the formation of dynamic microdomains referred to as lipid rafts in the membrane. Because the inside of a lipid domain is nonpolar and aprotic, it is of great interest to examine how cholesterol molecules are dissolved in low-polarity aprotic organic solvents that mimic the hydrophobic core of a phospholipid bilayer. Self-diffusion coefficients (D) are measured for normal (nondeuterated) and deuterated cholesterol in 1-octanol, chloroform, and cyclohexane at concentrations of 1-700 mM. The pulsed field gradient spin-echo (PGSE) ^1H and ^2H NMR were used, respectively, at 600 and 92 MHz. The hydrodynamic radius (R) obtained from D is the smallest in 1-octanol and it is comparable with the average length of the molecular axes for the cholesterol molecule. In 1-octanol, R is invariant against the concentration variation, whereas in chloroform, R is larger and increases almost linearly with cholesterol concentration. The R value larger than that in hydrogen-bonding 1-octanol indicates that cholesterol forms an aggregate through hydrogen bonding. The aggregate structure is confirmed by comparing NOESY spectra in chloroform and 1-octanol. The NOESY analysis reveals the presence of one extra cross peak (C4-C19) in chloroform compared to 1-octanol. Because the carbon atoms related to the cross peak are close to the hydroxyl group (C3-OH), cholesterol molecules are considered to be not piled but OH centered in the aggregate. This is supported also by larger rotational hydrodynamic radii measured on cholesterol deuterated at positions C2, C3, C4, and C6. This shows that the aggregate formation is driven by the hydrogen bonding between cholesterol molecules.

胆固醇参与了细胞膜中称为脂筏的动态微域的形成。由于脂类结构域的内部是非极性的和非质子的，因此研究胆固醇分子如何在模拟磷脂双层疏水核心的低极性非质子有机溶剂中溶解是非常有意义的。在浓度为1-700 mM的正辛醇、氯仿和环己烷中，测量了正常(非重氢)和重氢胆固醇的自扩散系数(D)。分别使用600 MHz和92 MHz的脉冲场梯度自旋回波(PGSE)^1H和^2H核磁共振。由D得到的流体动力学半径(R)在正辛醇中最小，与胆固醇分子的平均分子轴长度相当。在正辛醇中，R不随浓度变化而变化，而在氯仿中，R较大，且几乎与胆固醇浓度呈线性增加。R值大于氢键正辛醇的R值，表明胆固醇通过氢键形成聚集体。通过比较氯仿和正辛醇中的NOESY光谱，确定了聚集体结构。NOESY分析表明，与正辛醇相比，氯仿中存在一个额外的交叉峰(C4-C19)。因为与交叉峰相关的碳原子靠近羟基(C3-OH)，所以胆固醇分子被认为不是堆积在一起的，而是以羟基为中心的聚集体。在C2、C3、C4和C6位置测得的较大旋转流体动力学半径也支持这一点。这表明聚集体的形成是由胆固醇分子之间的氢键驱动的。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Mobility and Location of Anesthetics in Lipid Bilayer Membranes by High-Resolution, High-Field- Gradient NMR

通过高分辨率、高场梯度 NMR 确定麻醉剂在脂质双层膜中的迁移率和位置

DOI：
发表时间：
2005
期刊：
International Congress Series 1283
影响因子：
0
作者：
S.Ohno;et al.;Emiko Okamura et al.
通讯作者：
Emiko Okamura et al.

Dynamic and 2D NMR studies on hydrogen-bonding aggregates of cholesterol in low-polarity organic solvents.

DOI：
10.1021/jp062607t
发表时间：
2006-08
期刊：
The journal of physical chemistry. B
影响因子：
0
作者：
Cristiano Giordani;Chihiro Wakai;E. Okamura;N. Matubayasi;M. Nakahara
通讯作者：
Cristiano Giordani;Chihiro Wakai;E. Okamura;N. Matubayasi;M. Nakahara

Real-time in-cell 19F NMR study on uptake of fluorescent and nonfluorescent 19F-octaarginines into human Jurkat cells

DOI：
10.1246/cl.2005.1064
发表时间：
2005-07-05
期刊：
CHEMISTRY LETTERS
影响因子：
1.6
作者：
Okamura, E;Ninomiya, K;Nakahara, M
通讯作者：
Nakahara, M

Mobility and Location of Anesthetics in Lipid Bilayer Membranes by High-Resolution, High-Field-Gradient NMR

通过高分辨率、高场梯度 NMR 确定麻醉剂在脂质双层膜中的迁移率和位置

DOI：
发表时间：
2005
期刊：
International Congress Series 1283
影响因子：
0
作者：
村木孝仁;藤田賢一;寺門大;村木孝仁;Takahito Muraki;Cristiano Giordani et al.;Emiko Okamura et al.;Emiko Okamura et al.
通讯作者：
Emiko Okamura et al.