Nonfreezing water confined in water layer of multilamellar phospholipid

多层磷脂水层中限制的不冻水

• 批准号: 13640404
• 负责人: UTOH Shigenori
• 金额: $ 2.37万
• 依托单位: Fukuoka University of Education
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640404/
• 关键词: multilamellar phospholipid; water layer; super-cooled water; differential scanning calorimeter; X-ray diffraction; Raman scattering; non-freezing water; DSPC; ラマン散乱; DLPC; リン脂質集合体; 多層ラメラ; 極性頭部; 六方晶系状氷; X線回折

(1) The state of super-cooled water in the water layer of multilamellar L- α , distearoyl phosphatidylcholine (DSPC) containing 11wt% water remains unchanged even down to -190℃. Experimental results of differential scanning calorimeter(DSC), x-ray diffraction and Raman scattering prove that the super-cooled water in the water layer does not freeze even down to -190℃. Water layer is roughly divided into at least two regions : One region (tightly bound water layer) is precisely affected by the inner surface conditions such as hydrophilic interaction between the head group of DSPC and the water molecule, and the other region (loosely bound water layer) is bulk-like free water or is affected by relatively weak interactions correlated with distance from the surface. In the case of multilamellar phospholipid, the thickness of the water layer is estimated as 12〜30A equivalent to 4〜10 mono-layer thickness of water, however, multilamellar DSPC with 11wt% water contents is composed of only "tigh … More tly bound water layer" that is adsorbed on the surface of the polar head groups. This water region has a strong interaction with polar segments containing N^+ and O_-, and it modified their H-bonded network structure. The tightly bound water is considered to be nonfreezing water, because the attractive energy between bound water and hydrophilic head groups is greater than the ice nucleation energy.(2) Although the water layer of multilamellar L- α, dilauroyl (C_n = 12 : DLPC_<12>) phosphatidylcholine with water contents less than 10wt% is freezing during temperature decreasing down to - 140℃, the effect of hydrocarbon's length is relatively easy to remain the super-cooled water in the water layer in the case of multilamellar L - α , dilignoceroyl (C_n = 24 : DLPC_<24>) phosphatidylcholine. DSC thermal data are indicated that the state of super-cooled water or crystallization in water layer depends on the length of hydrocarbon chain in phospholipids.(3) Experimental results of Raman scattering show that a slight conformational change of multilamellar DSPC occurs at about - 130 ℃ on decreasing temperature process independently of whether the water layer is freezing or not. Less

(1)含11wt%水的多层L-α双硬脂酰磷脂酰胆碱的水层过冷水状态在-190℃下仍保持不变。差示扫描量热仪、X射线衍射仪和拉曼散射的实验结果表明，水层中的过冷水即使在-190℃以下也不会冻结。水层至少分为两个区域：一个区域(紧结合水层)精确地受到内表面条件的影响，如DSPC的头部基团与水分子之间的亲水作用，而另一个区域(松散结合水层)为块状自由水或受与表面距离相关的相对较弱的相互作用的影响。在多层磷脂的情况下，水层厚度估计为12~30A，相当于4~10层水的单层厚度，而水含量为11wt%的多层磷脂仅由吸附在极性头基团表面的“Tigh…更紧密的水层”组成。该水区与含有N^+和O-的极性链段有较强的相互作用，并改变了它们的氢键网络结构。由于束缚水与亲水头部基团之间的吸引能大于冰核能，因此认为紧束缚水为非凝固水。(2)多层L-α(C_n=12：DLPC_&lt；12&gt；)磷脂酰胆碱(C_n=12：DLPC_&lt；12&gt；)在降温至-140℃时，虽然水层结冰，但碳氢化合物长度的影响较容易将过冷水保留在水层中，对于多层L-α，磷脂酰胆碱(Cn=24：DLPC_&lt；24&gt；)差示扫描量热分析表明，水层中过冷水或结晶的状态取决于磷脂中碳链的长度。(3)拉曼散射实验结果表明，在降温过程中，多层膜的构象在-130℃左右发生了轻微的变化，与水层是否冻结无关。较少

项目成果

Shigenori Utoh: "Nonfreezing water confined in water layer of multilamellar L-α, distearoyl phosphatidylcholine in temperature range between 0℃ and -190℃"Journal of Chemical Physics. 115,No1. 601-607 (2001)

Shigenori Utoh：“0℃至-190℃温度范围内多层L-α、二硬脂酰磷脂酰胆碱的水层中的非冻结水”化学物理杂志115，No1 601-607（2001）。

Shigenori UTOH: "Nonfreezing water confined in water layer of multilamellar L-α, distearoyl phosphatidylcholine in temperature range between 0℃ and -190℃"The Journal of Chemical Physics. 115, No1. 610-607 (2001)

Shigenori UTOH：“0℃至-190℃温度范围内多层L-α、二硬脂酰磷脂酰胆碱的水层中的非冻结水”《化学物理杂志》115，No1（2001）。

Shigenori Utoh: "Nonfreezing water confined in water layer of multilamellar L-α, distearoyl phosphatidylcholine in temperature range between 0℃ and -190℃"Journal of Chemical Physics. 115, No1. 601-607 (2001)

Shigenori Utoh：“0℃至-190℃温度范围内多层L-α、二硬脂酰磷脂酰胆碱的水层限制的非冻结水”化学物理杂志115，No1（2001）。

Shigenori Utoh: "Nonfreezing water confined in water layer of multilamellar L-α, distearoyl phosphatidyicholine in temperature range between 0℃ and -190℃"Journal of Chemical Physics. 115,No1. 601-607 (2001)

Shigenori Utoh：“0℃至-190℃温度范围内多层L-α、二硬脂酰磷脂酰胆碱的水层限制的非冻结水”化学物理杂志115，No1 601-607（2001）。