Development of Active Transport and Ion-Channel Sensors

构建了三种不同类型的传感器。(1)利用Langmuir-Blodgett膜构建了一系列对有机和无机阴离子敏感的离子通道型传感器，这些传感器含有大环多胺和环糊精多胺的亲脂衍生物，能够以多质子化形式与阴离子客体结合。该传感器对多种客体阴离子（包括腺苷核苷酸、二羧酸盐和无机阴离子）的膜通透性表现出选择性响应（调节）。(2)将从大鼠脑突触膜分离的谷氨酸受体通道蛋白与平面双层脂质膜（BLM）结合，制备生物离子通道传感器。基于谷氨酸触发的单通道电流获得了2.1x10^5的信号放大。(3)从豚鼠肠刷状边界膜中分离Na^+/ d -葡萄糖共转运蛋白，将其纳入双层膜中，构建主动转运型d -葡萄糖BLM传感器。传感器的响应是在恒定的外加电位下由共输运Na^+离子通量引起的电导变化来测量的。10^<-9> M以上的d -葡萄糖能诱导传感器的响应，而相应的l -异构体、d -果糖和d -甘露糖则不能。

Three different types of sensors were constructed. (1) A series of ion-channel type sensors responsive to organic and inorganic anions were constructed utilizing Langmuir-Blodgett membranes containing lipophilic derivatives of macrocyclic polyamine and cyclodextrin polyamine, capable of binding with anionic guests in multiprotonated forms. The sensor showed selective response (modulation of membrane permeability to a number of guest anions including adenosine nucleotides, dicarboxylates and inorganic anions. (2) A biological ion-channel sensor was fabricated by incorporating glutamate receptorion-channel protein, isolated from synaptic membrane of rat brain, into a planar bilayer lipid membrane (BLM) . A signal amplification of 2.1x10^5 was obtained based on the glutamate-triggered single channel current. (3) A Na^+/D-glucose co-transporter protein, isolated from intestinal brush border membrane of guinea pigs, was incorporated into a bilayer membrane to construct an active transport type BLM sensor for D-glucose. The response of the sensor was measured as a conductance change arising from co-transported Na^+ ion flux under a constant applied potential. The response of the sensor was induced by D-glucose above 10^<-9> M, but not by the corresponding L-isomer, D-fructose and D-mannose.