用原子力显微技术研究乙酰胆碱与乙酰胆碱酯酶之间的作用力

建立了用原子力显微技术研究乙酰胆碱 (ACh)与乙酰胆碱酯酶 (AChE)分子间作用力的方法 .通过化学修饰将AChE固定于云母镀金表面 ,将ACh吸附于原子力显微镜的Si3 N4尖端 ,在对AChE成象基础上通过力谱线测量研究ACh与AChE分子间作用力 .结果表明两者间引力在相距 ( 3.94± 0 .5 )nm时可以测到 ,相互接触时为 ( 1 0± 1 )pN ;粘附力为 ( 2 5± 2 )pN .ACh水解产物Ch与AChE间的引力与ACh相似 ,粘附力略小于ACh ,为 ( 2 0± 2 )pN .这些结果证实AChE对乙酰胆碱具有导向作用 ,Ch难以通过活性中心离开乙酰胆碱酯酶 .     

Intermolecular forces between acetylcholine and acetylcholinesterases studied with atomic force microscopy

With the aid of atomic force microscopy, the intermolecular forces between acetyleholinesterases (AChE) and its natural substrate acetylcholine (ACh) have been studied. Through force spectrum measurement based on imaging of AChE molecules it was found that the attraction force between individual molecule pairs of ACh and AChE was (10±1) pN just before the quaternary ammonium head of ACh got into contact with the negative end of AChE and the decaying distance of attraction was (4±1) nm from the surface of ACHE. The adhesion force between individual ACh and AChE molecule pairs was (25±2) pN, which had a decaying feature of fast-slow-fast (FSF). The attraction forces between AChE and choline (Ch), the quaternary ammonium moiety and hydrolysate of ACh molecule, were similar to those between AChE and ACh. The adhesion forces between AChE and Ch were (20±2) pN, a little weaker than that between ACh and ACHE. These results indicated that AChE had a steering role for the diffusion of ACh toward it and had r     

Effects of trichlorfon on the contents of acetylcholine and choline in fish brain microdialysis samples by UPLC-MS/MS methodEI北大核心CSCD

A combination of microdialysis sampling with ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）was used to quantitatively analyze the effects of organophosphorus pesticides trichlorfon on acetylcholine （ACh） and choline （Ch） in the brain of crucian carp. The mechanism of organophosphorus pesticides poisoning was preliminarily discussed,showing that the ACh content in the brain of fish increased significantly with the increase of the exposure time to trichlorfon,while the Ch content decreased. It indicated that organophosphorus pesticides inhibited the activity of cholinesterase in organisms. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

乙酰胆碱酯酶AChE与1,7-二氮杂咔唑抑制剂的作用机理的分子动力学模拟

通过分子对接、分子动力学(MD)模拟以及成键自由能分析方法,从原子水平上模拟研究了3种1,7-二氮杂咔唑衍生物(分别记为M1、M2和M3)与ACh E的结合模式及相互作用机理,分析和讨论了研究体系的静电相互作用和范德华相互作用(vd W)。用MM-PBSA方法计算的3种抑制剂与ACh E之间的结合自由能与抑制剂的实验生物活性数据(IC50值)相对应。分析结果表明,残基S286与抑制剂之间形成的氢键作用有利于抑制剂与ACh E之间的结合。范德华相互作用,尤其是抑制剂与关键残基W279和Y334的作用,对抑制剂与ACh E之间的结合自由能有较大的贡献,在区分抑制剂M1(或M2)和M3的生物活性上发挥着重要的作用。     

氯灭酸与消炎痛稀土盐类的研究

在醋酸钠-甲醇溶液中,制备了两种非甾体抗炎药——氯灭酸、消炎痛的稀土盐类三十一个.研究了它们的溶解性,测定了它们的UV、IR、X射线粉末衍射、热谱和电导.确定化合物的组成为Ln(Ch)_3·nH_2O,Ce(Ch)_4·H_2O和Ln(Ind)_3·mH_2O(Ln=各种稀土离子;Ch=氯灭酸酸根;Ind=消炎痛酸根,n=1～2,m=3～5).动物试验表明,它们的毒性比相应的氯化物为小.     

高效液相色谱手性固定相法拆分四面体金属簇合物

在正相条件下,在Ch iralpak(AD-H和Ch iralcel(OD-H两种手性色谱柱上,首次直接拆分了三种外消旋过渡金属簇合物,考察了流动相中极性添加剂醇对手性拆分的影响.结果发现,氢键作用在手性识别过程中起重要作用,而且不同的色谱柱填料有不同的选择性.     

Synthesis and Evaluation of Two Novel Naphthol Derivatives as Novel Cholinesterase Inhibitors

Two novel naphthol derivatives(1 and 2) were synthesized and characterized via IR,~1H NMR,and HRMS.The structure of compound 2 was verified by single-crystal X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a = 21.6725(9),b = 6.0127(3),c = 25.5405(14) ?,β = 94.716(5)o,V = 3316.9(3) ?~3,Z = 8,F(000) = 1384,D_c = 1.511 Mg/m~3,M_r = 377.22 and μ = 2.487 mm~(-1).In addition,their cholinesterase inhibitory activities in vitro toward Electrophorus electricus acetylcholinesterase(eel ACh E) and horse serum butyrylcholinesterase(eq BCh E) were further determined.The results showed that compound 1 as a new acetylcholinesterase(ACh E) inhibitor displayed higher ACh E inhibitory activity(IC_(50) = 1.4 μM),which could be considered for Alzheimer's disease therapeutics.     

Preparation of AChE Inhibitors From Jujubogenin

The advanced medical technology has lengthened the life expectancy of human beings.This makes some previously ignored diseases prominent, such as Alzheimer disease(AD). The low level of acetylcholine (ACh) in brain is considered to be one of mainreasons for suffering such memory loss disease. Thereby, how to elevate ACh level inbrain and enhance the cognition has become a main issue l'2. One of the approaches is toinvestigate acetylcholinesterase (AChE) inhibitors, which can prevent the hy…     

基于功能化石墨烯-聚乙烯醇复合膜固定乙酰胆碱酯酶的甲拌磷传感器

将功能化离子液体修饰石墨烯(IL-GR)分散在聚乙烯醇(PVA)中,制得IL-GR-PVA分散液,与乙酰胆碱酯酶(ACh E)溶液混匀后滴涂在电极表面,利用PVA良好的成膜特性,制得新型有机磷检测酶电极ACh E/IL-GR-PVA/GCE,并用于有机磷农药的检测。采用透射电镜(TEM)表征了IL-GR的形貌,采用循环伏安法(CV)和差示脉冲伏安法(DPV)研究了酶电极的电化学性质。结果表明,IL-GR-PVA复合膜具有良好的导电性和生物相容性,能很好地保持ACh E的生物活性,并显著促进了其电化学过程。在优化实验条件下,抑制率(I%)与甲拌磷浓度的负对数在1.0×10-14~1.0×10-9mol/L和1.0×10-9~1.0×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为8.0×10-15mol/L。该传感器制备简单,稳定性好,灵敏度高,为有机磷农药的测定提供了新方法。     

毛细管电泳-电致化学发光法同时测定鼻炎康片中马来酸氯苯那敏和盐酸麻黄碱

基于马来酸氯苯那敏(Ch)和盐酸麻黄碱(Ep)同时增强联钌吡啶的电致化学发光信号特性,利用Ch和Ep在毛细管电泳分离时组分保留时间的差异,建立了毛细管电泳-时间分辨电致化学发光同时在线检测鼻炎康片中Ch和Ep含量的新方法。实验表明,在保持初始电位1.20V、运行高压为15kV、pH为10.5的NaH_2PO_4-Na2HPO_4缓冲液(添加10%乙腈和5%甲醇)的分离条件下,以及工作电极电位为1.2V、电动进样13kV和进样时间10s、pH=8的磷酸盐作为运行缓冲液的检测条件下,Ch和Ep在6min内可实现分离与检测,其线性范围分别为2.0×10~(-7)~2.0×10~(-4) mol/L和3.8×10~(-7)~6.0×10~(-4) mol/L,检出限分别为4.0×10~(-8) mol/L和1.5×10~(-8) mol/L(n=11),迁移时间的RSD分别为1.9%和2.2%,方法的RSD分别为3.9%和4.6%,方法回收率分别为97.97%和95.23%。     

基于氮掺杂多孔碳的乙酰胆碱酯酶传感器检测残留农药甲拌磷

以制备的新型氮掺杂多孔碳为载体,玻碳电极(GC)为工作电极,构建了乙酰胆碱酯酶(ACh E)传感器,用于有机磷农药甲拌磷的检测研究。在1.0 mmol/L底物氯化乙酰胆碱溶液中的差分脉冲扫描结果表明,ACh E/GC电极上的峰电流为0.195 8μA,而ACh E/氮掺杂多孔碳/GC电极上的峰电流为0.841 4μA,说明氮掺杂多孔碳材料可有效固定ACh E,提高检测灵敏度。采用ACh E/氮掺杂多孔碳/GC电极对不同浓度甲拌磷进行测定,在6.0×10-10~1.2×10-6g/L浓度范围内,抑制率与甲拌磷浓度的负对数呈良好的线性关系(r2=0.998 5)。按照抑制率为10%计算,检出限为5.8×10-12g/L。采用加标回收法检测菠菜汁样品中的甲拌磷,回收率为91.7%~97.4%。     

胆碱酯酶抑制剂萘酰亚胺衍生物的合成与聚集诱导发光性质

阿尔茨海默症(Alzheimer’s disease, AD)是一种神经退行性疾病,严重影响老年人的生活质量,目前治疗AD的药物主要是胆碱酯酶抑制剂,如多奈哌齐、卡巴拉汀等.本文基于多奈哌齐结构,设计合成了一系列新的萘酰亚胺衍生物并进行了活性评价.结果表明,所合成的化合物均对乙酰胆碱酯酶(AChE)有选择性抑制,其中2-((1-(3-甲氧基苄基)哌啶-4-基)甲基)-1H-苯并异喹啉-1,3(2H)-二酮(4k)的抑制活性最强,IC₅₀值为4.43μmol·L^-1,优于对照药物卡巴拉汀.酶动力学及分子对接表明4k能够同时作用于ACh E的催化活性位点和外周结合位点,并且4k对SH-SY5Y和PC12细胞毒性较低.此外,这些化合物均显示出典型的聚集诱导发光(AIE)性质,可能与萘酰亚胺分子内旋转受阻机制有关.     

The Role of Acetylcholine in the Cognitive Function of Frontal Neurons in Monkeys

To study the role of acetylcholine(ACh) in the cognitive function of frontal lobes, ACh and atropine were applied iontophoretically to the task-related neurons recorded from an area around the superior ramus of arcuate sulcus in the frontal cortex of 4 rhesus monkeys during the performance of two tasks. The spontaneous discharges and taskrelated responses of most of the neurons which increased their discharge rate in the delay and differentiation periods of the discrimination response go/no-go task and in the cue and delay periods of the delayed discrimination go/no-go task, were further increased during the application of ACh and suppressed during atropine. These results suggest that ACh may be involved in the excitatory process of the activity of the neurons in the above-mentioned area of frontal cortex to play an important role in the cognitive functions of attention, discrimination and short-term memory.     

基于铂/碳球的乙酰胆碱酯酶传感器在农药乐果检测中的应用研究

基于农药乐果对乙酰胆碱酯酶的抑制作用,构建生物传感器,实现了农药乐果的快速、高灵敏检测。合成了纳米材料铂/碳球(Pt/Cs),利用其比表面积大、导电性好的优势,构建乙酰胆碱酯酶(ACh E)传感器。铂/碳球修饰电极比裸电极的阻抗更低,峰电流增加了147.06%,说明该材料能很好地保持酶的催化活性。在最优实验条件下,用ACh E传感器检测农药乐果,在1.0×10~(-9)~1.0×10~(-6)g/L范围,乐果浓度的负对数与抑制率呈良好的线性关系,其检出限为7.3×10~(-12)g/L(按抑制率为10%计算)。对纺织品样品进行加标回收实验,测得回收率为86.2%~101.7%。     

Nafion/胆碱双层膜碳纤维电极探测小白鼠大脑内的多巴胺

制备了胆碱(Ch)共价键植的碳纤维电极(Ch/CFE),进而吸附涂敷一薄层Nafion膜得到了Nafion/Ch/CFE。以循环伏安(CV)法和差分脉冲伏安(DPV)法研究了该电极上多巴胺(DA)的电化学响应。使用DPV法,该电极能良好抵抗代谢产物3,4-二羟苯乙酸(DOPAC)和抗坏血酸(AA)的干扰而选择性测量DA。在1.0 mmol/L AA存在下,使用5 mm长Nafion/Ch/CFE测定DA,检出限(S/N=3)为0.1μmol/L;线性范围为0.4~16μmol/L。该电极适于活体监测。将该电极插入小白鼠大脑纹状体内,实时监测了神经递质DA的浓度及其变化,观察到DA水平由静脉注射药物左旋多巴(L-DOPA)后随时间的响应,并发现针刺激对应于中医"风府穴"的头部皮下组织可引起脑内DA的即时性脉冲释放。     

黄藤素衍生物的合成及其抑制乙酰胆碱酯酶活性研究

对黄藤素进行结构修饰,采用160~180℃高温热解使黄藤素选择性在9-位脱甲基,再分别与一系列酰氯发生酯化反应,最终获得12种黄藤素衍生物,经~1H-NMR、~(13)C-NMR分析确定了各衍生物的化学结构,分别为:9-O-苯甲酰基-黄藤素(9-O-Benzoyl-fibrauretin)、9-O-(2-甲基苯甲酰基)-黄藤素(9-O-(2-Methylbenzoyl)-fibrauretin)、9-O-(4-甲基苯甲酰基)-黄藤素(9-O-(4-Methylbenzoyl)-fibrauretin)、9-O-(3,5-二甲基苯甲酰基)-黄藤素(9-O-(3,5-Dimethylbenzoyl)-fibrauretin)、9-O-(4-(氯甲基)苯甲酰基)-黄藤素(9-O-(4-(Chloromethyl)benzoyl)-fibrauretin)等共12种化合物,均为新化合物。采用以碘化硫代乙酰胆碱为底物、来源于苍蝇头部的乙酰胆碱酯酶(ACh E)为酶源的体外活性测定方法,测定了黄藤素及其衍生物的ACh E抑制活性。结果表明,大部分黄藤素酰氯衍生物体外ACh E抑制活性均强于黄藤素,其中化合物9-O-(4-甲基苯甲酰基)-黄藤素、9-O-(3,5-二甲基苯甲酰基)-黄藤素、9-O-(4-(氯甲基)苯甲酰基)-黄藤素对ACh E的抑制作用显著,活性强度强于阳性药盐酸多奈哌齐,具有开发成抗阿尔茨海默症药物的潜力。     

锌与小儿神经系统及代谢性疾病

综述了锌在小儿神经系统疾病和内分泌代谢性疾病中的作用及临床意义，尤其是对癫痫的发病起重要作用，大量资料证明高锌与癫痫发作有关，其血锌值明显高于健康儿童，因此在治疗中不要轻易补锌。还综述了锌与智能发育障碍、生长发育障碍、多动症、胎儿畸形、遗传性感音神经性聋等疾病的关系及在治疗糖尿病、肝豆状核变性等内分泌和代谢性疾病时要注意维持锌的正常动态平衡。     

2011第25届欧洲传感器会议

本届会议于2011年9月4日至7日在希腊首都雅典市Magaron雅典国际会议中心(AICC)召开。全体会议上分别由Ch Tsamis与G Kaltasas教授作报告,就欧洲传感器会议1987成立以来的工作进行总结以及提出今后的展望。会议的内容涉及传感器、传动器、振动器以及其他固态有关的微系统与纳米级系统。     

基于电化学方法检测花生油中黄曲霉毒素B1

基于黄曲霉毒素B1(AFB1)对乙酰胆碱酯酶(ACh E)的抑制作用,建立了ACh E电流型酶传感器,对食品中的AFB1进行快速检测。在最优条件下,AFB1质量浓度在2.00~7.00μg/m L范围内与传感器的响应呈线性关系,线性方程为A(%)=8.24057ρ+8.02743(%),检出限为0.89μg/m L。实际样品加标的平均回收率为96.3%~108.8%。方法适用于现场快速检测。     

Effects of Muscle Electrical Activity on the Transmission of Developing Neuromuscular Junction

Miniature endplate potentials (MEPPS) caused by the spontaneous release of ACh from the growth cone of cholinergic neurons, are recorded by the whole-cell patch-clamp technique on a large number of 1-day cultured myoballs which have contact neurites of co-cultured neurons. Both muscle cell and neuron are dissociated from the 1-day-old (about stage 20) Xenopus embryo. Frequency and/or amplitude of MEPPs can obviously increase after the repetitive high-level depolarization caused by the stimuli on muscle cells. No detectable changes of single ACh receptor channel property are observed by using the single-channel recording technique. These results suggest that the mechanism of the increase of MEPPs after electrical activity of postsynaptic muscle cells probably involve some alteration of presynaptic membrane.