第46回 アイセムスセミナー / CeMI セミナーシリーズ 14: 山越 葉子 博士

CeMICenter for Meso-Bio Single-Molecule Imaging

Tripod-shaped molecules were designed for chemical modification of the surface of probes used for atomic force microscopy (AFM). These chemically functionalized tips were used for chemical force spectroscopy (CFS) measurements of the ligand-protein receptor interaction in a biotin-NeutrAvidin model system. We demonstrate that by using this unique tripodal system, we can achieve significantly lower density of ligand on the AFM tip apex, which is optimal for true single molecule measurements. Furthermore, the molecular tripods form highly stable bonds to the AFM probes, leading to more robust and reproducible unbinding force data, thereby addressing one of the challenges in CFS studies. Histogram analysis of the hundreds of collected unbinding forces showed a specific distribution with a peak force maximum at ~165 pN, in good agreement with the previously reported data of single rupture events of biotin-avidin. We compared these molecular tripod tips with molecular monopod. The results showed that the molecular tripods are more robust for repeated measurements. The distinct biotin-avidin force maximum was not observed in the control experiments. This indicated that the force distribution observed for molecular tripods corresponds to the specific rupture force between biotin and avidin. The improved robustness of molecular tripods for CFS will provide benefits in other ligand-receptor unbinding studies, including those of transmembrane receptor systems, which require high resolution, sensitivity, and reproducibility in force spectroscopy measurements.

講演者 山越 葉子 博士
Assistant Professor, Department of Radiology / Department of Chemistry
米国 ペンシルバニア大学
演題 Synthetic Chemistry for AFM Tip Modification and Biological Applications
日時 2010年3月3日(水)10:30-11:30
場所 京都大学 iCeMSコンプレックス1 本館 2階 セミナールーム (A207)
アクセスマップ
フライヤー PDF FilePDF (268KB)
主催 京都大学 物質-細胞統合システム拠点(iCeMS=アイセムス)
連絡先 iCeMS原田グループ
harada-g@icems.kyoto-u.ac.jp