Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Illinois 61801, USA.
ACS Nano. 2012 Oct 23;6(10):8847-56. doi: 10.1021/nn3027408. Epub 2012 Aug 21.
Surface immobilized biomolecular probes are used in many areas of biomedical research, such as genomics, proteomics, immunology, and pathology. Although the structural conformations of small DNA and peptide molecules in free solution are well studied both theoretically and experimentally, the conformation of small biomolecules bound on surfaces, especially under the influence of external electric fields, is poorly understood. Using a combination of molecular dynamics simulation and surface-enhanced Raman spectroscopy, we study the external electric field-induced conformational change of dodecapeptide probes tethered to a nanostructured metallic surface. Surface-tethered peptides with and without phosphorylated tyrosine residues are compared to show that peptide conformational change under electric field is sensitive to biochemical modification. Our study proposes a highly sensitive in vitro nanoscale electro-optical detection and manipulation method for biomolecule conformation and charge at bio-nano interfaces.
表面固定化生物分子探针在基因组学、蛋白质组学、免疫学和病理学等许多生物医学研究领域都有应用。虽然在理论和实验上都对游离溶液中小 DNA 和肽分子的结构构象进行了很好的研究，但对于结合在表面上的小分子生物分子的构象，特别是在外部电场的影响下的构象，还了解甚少。本研究采用分子动力学模拟和表面增强拉曼光谱相结合的方法，研究了束缚在纳米结构金属表面上的十二肽探针在外加电场作用下的构象变化。比较了带有和不带有磷酸酪氨酸残基的表面束缚肽，表明电场下的肽构象变化对生化修饰敏感。本研究提出了一种在生物纳米界面处对生物分子构象和电荷进行高灵敏度的体外纳米级光电检测和操控的方法。
