Study of the planar membrane on the silica compounds and its application

我们已经研究了抗体依赖性结合的巨噬细胞支持平面脂质单层含有半抗原磷脂。巨噬细胞与平面DMPC或DPPC单层的结合依赖于IgG亚类和半抗原浓度。在“固体”和“流体”脂质单层膜上的结合效率如下：IgGl IgG 2a IgG 2b IgG 3。接下来，我们通过纳秒荧光测定法确定了半抗原（TNP和丹磺酰）在脂质双层膜中的位置。结果发现，即使半抗原的TNP（或丹酰）残基具有不同长度的间隔区，它们在膜表面的垂直位置也是相似的。从这些类型的实验中，解释了间隔区长度如何可以调节抗体分子与膜中的脂质半抗原的结合亲和力。最后，我们研究了一种新型的免疫场效应晶体管，它是通过含有脂质半抗原的单层脂质体（TNP-Cap-DPPE）的融合，在ISFET的栅极（Si_3N_4/SiO_2）表面形成脂质膜。当加入鼠抗TNP单克隆抗体IgG_1后，用pH/pCO_2监测仪观察到5- 10 mV的负电位变化。对于对照实验，将非特异性muse IgGl加入溶液中，未观察到潜在变化。

We have studied the antibody-dependent binding of macrophages to supported planar lipid monolayers containing haptented phospholipids. The binding of macrophages to planar DMPC or DPPC monolayers was dependent on IgG subclasses and hapten concentrations. The binding efficiencies were as follows on both 'solid' and 'fluid' lipid monolayer membranes; IgGl IgG2a IgG2b IgG3. Next, we determined the location of haptens (TNP and dansyl) in lipid bilayer membranes by nanosecond fluorometry. It was found that TNP (or dansyl) residues of lipid haptens locate at the similar vertical position on the membrane surfaces even if they have different length spacers. From these kinds of experiments it was explained how the spacer length can modulate the binding affinity of antibody molecules to the lipid hapten in the membrane. Lastly, we have studied a new type of immuno-FET which has lipid membranes on the surface of an ISFET gate (SI_3N_4/SiO_2) by the fusion of single unilamella liposomes containing lipid haptens (TNP-Cap-DPPE). When mouse monoclonal anti-TNP IgGl was added to the solution, a time-dependent potential change (5-10mV) towards negative was odsedved by a pH/pCO_2 monitor. As for a control experiment, non-specific muse IgGl was added to the solution, no potential change was observed.