14:45 〜 15:00
▲ [18p-E302-6] The adsorption measurement of CNT-binding peptide-modified cage-shaped proteins
キーワード：CNT, Aptamer, peptide adsorption
We proposed a novel CNT/protein/CNT junction for nanodevices. The outer-surface of a cage shaped protein could genetically modified to bind to CNT and fabricate a heterojunction, “CNT/protein/CNT. The heterojunction can alter the properties of CNT composites to enable a wide range of applications. [1] We used the Ph.D.-12 phage display system for the aptamer SELEX (Systematic evolution of ligands by exponential enrichment) and panning out high-affinity CNT aptamers. The selected high frequency appearing aptamers had similar hydrophobic positions and three-dimensional simulated structures.[2] We added these short peptides (See Fig1.) on the C- terminal of Dps (The DNA-Binding Protein from Starved Cells) subunit, and measured their adsorption using electrochemical impedance spectroscopy (EIS). EIS measurements were performed in PBS solution containing 3 mM ferricyanide and ferrocyanide. After equilibration, 1 mg/mL, 3 mg/mL, 10 mg/mL and 30 mg/mL of protein or peptide were added sequentially and EIS was measured in 5 min. interval. We use the highly oriented pyrolytic graphite (HOPG) as a working electrode. The HOPG can simply produce a new surface with removing the surface layer. The HOPG new surface was polished with 1 mm Diamond particles 5 minus and used for the EIS working electrode. The super-graphite was also used.
We can see the wild type Dps (wDps) protein has a low binding affinity for both HOPG and PSG. Among the modified Dps, Y1Ct-Dps has the best binding affinity. In the case of PSG, Y2Ct-Dps shows low binding affinity, but in the case of HOPG, it does not differ from wDps. Even Y1Ct-Dps also shows lower affinity in HOPG than in PSG. The carbon surface affect the aptamer adsorption. We will compare the results of different materials to further clarify how the Carbon surface interaction with the aptamers.
We can see the wild type Dps (wDps) protein has a low binding affinity for both HOPG and PSG. Among the modified Dps, Y1Ct-Dps has the best binding affinity. In the case of PSG, Y2Ct-Dps shows low binding affinity, but in the case of HOPG, it does not differ from wDps. Even Y1Ct-Dps also shows lower affinity in HOPG than in PSG. The carbon surface affect the aptamer adsorption. We will compare the results of different materials to further clarify how the Carbon surface interaction with the aptamers.