We propose to develop an imaging platform to map chemical identities and mechanical behaviors across cells and sub-cellular structures with unprecedented resolution. Currently, both transmission electron microscopy (TEM) and fluorescence microscopy technologies are going through a revolution, one in chemical selectivity and the other in spatial resolution. However, neither TEMs can image functional biological systems in solution nor fluorescence microscopy can provide atomic scale resolution. Our proposed imaging platform uses a radically different approach to provide chemical information on the Angstrom scale in solution environment. We developed a scheme to encode chemical information in energy landscapes of small biomolecules and a nanomechanical device to decode this information rapidly. The chemical information can be encoded into target molecules through genetic manipulations, which will lead to the mechanical analogue of the green fluorescent protein technology. Our proof of principle experiments have demonstrated that chemically-specific multicolor images of biomolecules can be obtained with sub-nanometer resolution in a solution environment. We propose to develop this concept into an imaging platform that can target a wide variety of proteins and other biomolecules across living cells and in isolated complexes. The capabilities of the new imaging platform will go beyond chemical identification and allow probing interactions among biomolecules, which collectively determine the mechanical behavior of cells. An accurate description of the biological state of a cell has to include more than its biochemical composition and their spatial arrangements, because mechanical behaviors of cells influence normal and diseased cellular processes. The new imaging platform will allow determining the mechanical state of cells by providing information on local compression-tension and elastic-viscoelastic characteristics at unprecedented spatial and temporal resolution. We will further combine the new nanomechanical imaging platform with fluorescence microscopy including super-resolution methods to dissect the molecular basis of the observed dynamic mechanical characteristics. Once developed, we will apply this technology to problems in cell mechanics, adhesion, synaptic plasticity and structure determination of macromolecular complexes. The technology and instrumentation developed in this project will have a broad impact in a wide range of biomedical fields and technologies.
|Kim, Duckhoe; Sahin, Ozgur (2015) Imaging and three-dimensional reconstruction of chemical groups inside a protein complex using atomic force microscopy. Nat Nanotechnol 10:264-9|