二亚油酰磷脂酰胆碱分析

通过HPLC/HPLC-MS研究了二亚油酰磷脂酰胆碱的测定方法,磷脂样品首先经过HPLC分离得到磷脂酰胆碱,该磷脂酰胆碱再进一步通过不同的HPLC系统分离二亚油酰磷脂酰胆碱,并通过标准样品和质谱进行二亚油酰磷脂酰胆碱的定性.定量方法通过标准样品外标法定量,由方法的回收率和精密度试验可知,该方法已用来测定一般磷脂样品和磷脂酰胆碱样品中的二亚油酰磷脂酰胆碱含量.     

磷脂酰胆碱水溶液CMC的测定

磷脂酰胆碱水溶液ＣＭＣ的测定陈鲁生周武姜云生（山东师范大学化学系济南２５００１４）关键词磷脂酰胆碱临界胶束浓度磷脂酰胆碱是一种天然生物两性表面活性物质，也是一种重要的生命物质，具有广泛的用途［１］，由于磷脂酰胆碱的水溶性较差，所以较长时间以来对其溶液...     

铕对磷脂酰胆碱LB单分子膜结构影响的原子力显微镜观察

用原子力显微镜观察到亚相中Eu^3^+诱导二棕榈酰磷脂酰胆碱Langmuir-Blodgett(LB)单分子膜出现有规则周期性条纹结构。     

含芳基磷脂酰胆碱类似物的合成

磷胆酰胆碱;磷脂类似物;酰化;含芳基磷脂酰胆碱类似物的合成     

磷脂酰胆碱与牛血清白蛋白相互作用的FT-IR研究

利用傅立叶变换红外(FT-IR)和拉曼(FT-Raman)光谱研究了高浓度磷脂酰胆碱(PC)与牛血清白蛋白(BSA)的相互作用,及Eu3＋对该作用的影响.FT-IR结果显示,PC/BSA混合体系中二者的相互作用主要发生在PC头部极性基团,且这一作用随BSA含量的增加而增强,作用后蛋白质二级结构中α螺旋的比例有所增加. FT-Raman光谱说明PC与BSA的相互作用影响磷脂CH链的排列有序程度. PC/BSA/Eu3＋体系的红外光谱显示, Eu3＋与PC的磷氧键发生了强相互作用,并使蛋白α螺旋的比例进一步增加.     

电化学方法研究多粘菌素B与磷脂酰胆碱的相互作用

采用电化学方法研究了一种多肽类抗生素多粘菌素B(PMB)与模拟生物膜硫醇-磷脂酰胆碱杂化双层膜之间的相互作用。PMB可与磷脂酰胆碱发生强相互作用,破坏双层膜结构,从而使膜的通透性升高。PMB的浓度、酸度、与膜的作用时间及膜中胆固醇的存在均影响二者的作用程度。另外,膜的自修复实验表明,被PMB破坏的双层膜电极在一定程度上可以在KCl溶液中重新自组装,且自修复的程度和修复时间及与之相互作用的PMB的浓度有关。     

高效液相色谱-蒸发光散射法测定甘油磷脂酰胆碱

建立了高效液相色谱-蒸发光散射法(HPLC-ELSD)测定甘油磷脂酰胆碱(L-α-GPC)的方法。得到最佳色谱条件:色谱柱为Tigerkin Diol柱(250×4.6mm,5μm),流动相为甲醇-水(体积比90∶10),氮气流量为1.50L/min,漂移管温度为65℃。用外标法对L-α-GPC和磷脂酰胆碱(PC)进行定量分析,线性范围分别为0.25~3.00g/L和0.50~5.00g/L,相关系数分别为0.9993和0.9987;平均回收率分别为95.87%和95.72%;相对标准偏差分别为1.75%和1.93%。该方法能够简便快速的将L-α-GPC与其他磷脂进行分离。     

大豆磷脂中磷脂酰胆碱的脂肪酸组成分析

1　引　　言磷脂是生物膜的主要成分 ,是由甘油骨架、极性基团和不饱和脂肪酸组成的脂质类化合物。磷脂种类 (ＰＣ ,ＰＥ等 )的化学组成决定磷脂的物理特性 ,进而影响生物膜的功能。研究表明 :磷脂脂肪基团中不饱和碳 碳键是决定其相变温度的关键因素 ,同时 ,环境因素影响磷脂的脂肪酸组成 ,随环境温度的变化 ,磷脂的脂肪酸组成也作出相应的调整。因此 ,测定磷脂酰胆碱的脂肪酸组成 ,对研究大豆的遗传性及环境因素对其所造成的影响具有重要意义。磷脂脂肪酸组成的分析已有报道 ,但对于大豆磷脂酰胆碱脂肪酸组成的分析国内至今未见报道。本…     

含磷脂酰胆碱的聚乳酸的诱导矿化研究

分别以甘油磷脂酰胆碱和1,4-丁二醇为引发剂开环丙交酯,制备了含磷脂酰胆碱的聚乳酸(PLA-PC)和聚乳酸(PLA),比较了两者在诱导矿化中的差异.用傅立叶红外光谱仪(FTIR)、X-射线衍射仪(XRD)和扫描电子显微镜(SEM)对PLA-PC膜表面形成的矿化物进行了表征.结果表明,形成的矿化物为羟基磷灰石(HAP),PLA-PC膜有利于成核和生长,晶体呈片状,并随矿化时间延长,HAP晶粒逐渐增大,晶片厚度也逐渐变大.     

高效液相色谱法测定大豆磷脂类保健食品中磷脂酰胆碱

建立了高效液相色谱法测定大豆磷脂类保健品中磷脂酰胆碱含量的方法。样品经丙酮溶解去除油脂类杂质干扰后,离心弃去上层液体,残液用氮气吹干,然后用正己烷-异丙醇(1+1)混合液溶解残渣,以正相硅胶柱(250mm×4.6mm,5μm)为固定相,以乙腈-甲醇-磷酸(80+20+0.6)溶液等度洗脱分离,用紫外检测器于波长205nm处检测。磷脂酰胆碱的质量浓度在2.136g·L-1以内与其峰面积呈线性关系。应用此法分析大豆磷脂软胶囊,平均回收率在90.2%～96.1%之间;测定值的相对标准偏差(n=6)在1.2%～3.6%之间。     

A Micromechanical Cantilever‐Based Liposome Biosensor for Characterization of Protein‐Membrane Interaction

We have newly evaluated the interaction of lipid membrane with two different proteins of lysozyme and carbonic anhydrase from bovine (CAB) using a micro cantilever‐based liposome biosensor with a new droplet‐sealing structure. Herein 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC) liposomes are used as model lipid membrane and are immobilized on the surface of cantilever. The interaction of DPPC liposome with the target protein causes deflection of the micro‐cantilever, which can stably be detected by measuring the resistance change of the strain gauge. The resistance change dependent on time is used to evaluate the characteristic of liposome‐protein interaction. The resistance of the cantilever‐based biosensor increases monotonously with time in both of the two protein solutions. Especially, chronological resistance change depends markedly on both the concentration and species of target proteins. Finally, these results lead us to conclude that the cantilever‐based liposome biosensor with the droplet‐sealing structure facilitates the characterization of protein‐membrane interaction. It also means that this biosensor is a promising candidate device for label‐free detection of concentration and species of different target proteins.     

脂质体电动色谱法评价阿魏酸与生物膜的相互作用

利用脂质体与生物膜结构的相似性,将脂质体加入毛细管电泳缓冲溶液中作为假固定相,在数分钟内测定了阿魏酸的脂水分配系数Klw,建立了脂质体电动色谱评价阿魏酸与生物膜相互作用的方法。研究了脂质体中胆固醇的含量、缓冲溶液pH值和缓冲体系对Klw的影响。结果表明,在实验条件范围内(胆固醇含量0~30%,pH值4.0~12.0),胆固醇含量升高,缓冲溶液pH值增大,Klw降低;在不同的缓冲体系中,离子强度越大,Klw越大。脂水分配系数的变化反映了阿魏酸与生物膜相互作用。     

Interaction of Dipalmitoyl Phosphatidylcholine with n‐Hexadecanol in Monolayer and Liposome

The monolayer collapse behavior of n‐hexadecanol/dipalmitoyl phosphatidylcholine (DPPC) was investigated in this study at the air/water interface at 37 °C. Surface pressure variations with time for the mixed monolayers of DPPC with 20 mol% and 50 mol% n‐hexadecanol at corresponding collapse points were recorded by a Langmuir trough system. In addition, the interaction of n‐hexadecanol with a pure DPPC monolayer was identified by fluorescence microscopy (FM). The results demonstrated distinct differences between these systems; according to our observation, the higher the ratio of n‐hexadecanol to DPPC, the more nucleation domains can be induced. The FM images demonstrated that pronounced domain formation was associated with a longer relaxation time of the collapsed DPPC and DPPC/n‐hexadecanol monolayers, and the presence of n‐hexadecanol appeared to enhance the relaxation processes. The liposome was prepared by the thin‐film hydration method. The average diameter of DPPC and DPPC/n‐hexadecanol liposomes was investigated by dynamic light scattering. It is shown that the diameter of DPPC liposome with n‐hexadecanol is smaller than pure DPPC liposome at the initial state. After 24 hours, DPPC/n‐hexadecanol liposome became larger than pure DPPC liposome and lasted for the next four days. The effects of a greater ratio of n‐hexadecanol did not play an important role in DPPC liposome formation based on our dynamic light scattering analysis. Our result demonstrated that n‐hexadecanol might affect the DPPC liposome stability. The increased ratio of n‐hexadecanol in DPPC liposomes could only a play a minor role in DPPC liposome fusion.     

锌金属硫蛋白预防甲基汞对细胞膜损伤作用的实验研究

不同剂量的Ｚｎ可以诱导小鼠肝脏产生ＺｎＭＴ,随着实验组Ｚｎ剂量的增加,肝脏内ＺｎＭＴ的含量也相应增加,呈剂量效应增加（ｒ＝０．９９６）。ＺｎＭＴ具有保护膜构象、膜ＳＨ基、拮抗ＭｅＨｇ对膜流动性及膜通透性的损伤作用。本实验结果为ＺｎＭＴ预防甲基汞中毒提供了科学依据,同时显示了诱导ＺｎＭＴ的锌剂量要适当,过高则有毒性作用。     

壳聚糖膜结构与乙醇／水混合液的渗透汽化性能

用渗透汽化膜分离混合液体,纤维素、赛璐玢等作醇/水分离膜有较高的渗透通量,但分离系数低.甲壳素是广泛存在于自然界的一类天然高分子.前文报道了用甲壳素脱乙酰基的产物壳聚糖(CS)作醇/水渗透汽化(PV)分离膜,在一定的原料液浓度下具有较好的选择渗透性.本文讨论CS膜结构对乙醇/水混合液PV性能的影响,并探讨了提高选择性的途径.     

Structure Characteristic and Catalase Activity of Vitreoscilla Hemoglobin Bound with Membrane

Lipid-bound [VHb(406)] and lipid-free [VHb(402)] wide type Vitreoscilla hemoglobin were separated from E. coli BL21(DE3). The RZ is 3.30 for [VHb(406)] and 3.15 for [VHb(402)], respectively. VHb(406) shows a characteristic absorption band at 626 nm, while VHb(402) shows one at 644 nm, and it has more α-helix than VHb(402). Data of Raman spectra experiment shows under the excitation wavelength 488 nm, υ4 vibration of both VHb(402) and VHb(406) had a pure and strong signal at 1375 cm-1, which proves that iron...     

A Cantilever‐based Biosensor for Real‐time Monitoring of Interactions between Amyloid‐β(1–40) and Membranes Comprised of Phosphatidylcholine Lipids with Different Hydrophobic Acyl Chains

Accumulating evidence suggests that interaction between amyloid‐β (Aβ) and cell membrane is crucial to the pathogenesis of Alzheimer's disease (AD), and thus an increasing understanding of the impact of membrane composition on Aβ‐membrane interaction becomes essential for the mechanism elucidation of Aβ‐membrane interaction and the early diagnosis of AD. In this work, electrically neutral phosphatidylcholine (PC) as the most major class of membrane phospholipids, including 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC), 1,2‐distearoyl‐sn‐glycero‐3‐phosphocholine (DSPC), 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC), and Aβ(1–40) as the most common amyloid protein were selected as the research subjects, and a developed cantilever‐based biosensor, on which liposomes comprised of PC lipids were immobilized, was applied to characterize in real time the interactions between Aβ(1–40) and membranes comprised of PC lipids with different hydrophobic acyl chains, and to evaluate the effect of cholesterol incorporated in membrane on Aβ‐membrane interaction during the whole process of Aβ(1–40) fibrillization. The results illustrate that the interaction between Aβ(1–40) and PC membrane can be divided into three stages, which are related to the change in molecular states of Aβ. More importantly, it is found that membranes comprised of PC lipids with shorter saturated acyl chains show higher interaction ability with Aβ(1–40), and the incorporation of cholesterol into PC bilayer can remarkably accelerate and strengthen Aβ(1–40)‐membrane interaction. These results confirm that hydrophobicity is the main driving force for the interactions between Aβ(1–40) and PC membranes. In return, the above results enlightened us to apply the current micro‐cantilever immobilized with cholesterol‐containing DPPC liposomes to challenge the detection of low‐concentration Aβ(1–40). This time 50‐nM Aβ(1–40) in aqueous solution has been effectively detected, suggesting that this proposed detection technique would contribute to Aβ detection and early diagnosis of AD in the future.     

季铵盐型Gemini表面活性剂诱导囊泡结构改变机理研究

用动态光散射技术以及荧光探针方法, 研究了不同连接基长度的季铵盐型Gemini表面活性剂对卵磷脂囊泡结构改变的影响, 并借助理论模型和临界堆积参数理论探索了Gemini表面活性剂诱导囊泡结构改变的机理. 实验结果表明, 表面活性剂诱导囊泡结构改变的主要原因是表面活性剂嵌入到囊泡的双分子层中, 从而改变了囊泡的表面电荷强度以及嵌入后的表面活性剂在囊泡双分子层中分布的不均匀性. 此外, 表面活性剂分子的结构也会对其产生影响, 不同连接基长度的季铵盐型Gemini表面活性剂对囊泡结构改变的影响不完全相同, 但会呈现出一定的规律性.     

尼古丁与DNA相互作用的电化学研究

用线性扫描伏安法、循环伏安法及光谱法研究了尼古丁与DNA在0.2 mol/LpH 6.0的H2C2O4缓冲溶液中的相互作用。研究结果显示,随着DNA的加入,尼古丁峰电流降低,峰电位正移,说明尼古丁是以嵌入形式与DNA结合,生成了一种结合比为2∶1的非电活性化合物,结合常数β为1.56×109。并用多种电化学方法求得了电极过程的动力学参数。     

膜富集结合膜上图像比色法快速检测微量有机磷农药

建立了基于手机图像比色法结合多通道膜富集技术用于微量有机磷农药的快速检测方法. 根据乙酰胆碱酯酶活性受有机磷农药特异性抑制而降低的特点, 以吲哚乙酸酯为底物, 经酶水解生成靛蓝, 利用多通道膜富集装置将有色生成物富集到尼龙微孔滤膜上, 将标准溶液和样品溶液富集在同一张膜的不同位置. 用智能手机拍摄微孔滤膜的数码照片, 利用编制的手机APP软件对照片进行处理, 消除光照、 噪点等的影响, 可实现自动识别标准和未知样品. 通过提取样品颜色信号, 建立了颜色信号与浓度的定量分析模型, 用其检测敌百虫的检出限可达0.030 mg/L. 利用该方法对黄瓜中农药敌百虫的含量进行分析, 加标回收率在95.8%~106.9%之间, 相对标准偏差RSD(n=5)为3.8%~5.4%. 本方法用手机代替光谱仪, 简单实用, 与相关国标方法相比, 灵敏度和准确度均得到显著提高, 具有良好的应用前景.