We are proposing a technology to help in three key areas of proteomics including (a) recognition of protein interactions, (b) characterization of post translational modifications, and (c) quantitative measurements at high spatial and/or temporal resolution to address the dynamics of protein interactions. Several significant types of protein interactions remain difficult to study with existing technologies. For example, the analysis of membrane protein interactions (mostly glycol proteins) is challenging, because these proteins are not stable outside of their native amphiphilic cellular environment. Analysis of interaction kinetics between small molecules (<500 Da, including a vast majority of metabolites and drugs) and proteins is also lacking, because these molecules are too small for fluorescence labeling, and the binding signals are too weak for label-free detection methods. Similarly problematic is the characterization of protein post-translational modifications, which alter protein behavior due to the attachment of a small functional group after translation. Specifically, we propose an electrochemically-enhanced plasmonic imaging (ECEPI) system to address key needs for quantitative analysis of protein interaction dynamics, including the ability to study membrane protein interactions in their native cellular state, characterization of small molecule interaction and post-translational modifications, measurement of interactions at high spatial and temporal resolution for the study of sub-cellular processes, and performing high-throughput analysis in multi-cellular and microarray formats. The ECEPI system relies upon careful integration of three core technologies: 1) the electrochemical surface plasmon resonance systems that have been successfully commercialized by Biosensing Instrument Inc. (BI) for their unique capabilities and solid performance, 2) a proprietary high resolution distortion-free prism-based surface plasmon resonance (SPR) imaging system currently under development at BI for high-throughput interaction analysis, and 3) a highly sensitive impedance imaging technique invented at Arizona State University. The success of this project will lead to a new instrument that is capable of: 1) Label-free real-time recognition and quantification of protein interaction kinetics; 2) Real-time characterization of post-translational modifications of proteins; 3) Quantitative measurement of small molecule interactions with proteins; 4) In situ quantification of membrane protein (and glycoprotein) interactions in their native cellular environment with cell-based assay; 5) High-resolution analysis of sub-cellular processes and; 6) High-throughput analysis in multi-cellular and microarray formats
This project aims to develop an electrochemically-enhanced plasmonic imaging (ECEPI) system that enables high-throughput analysis of protein interactions with small molecules and characterization of post-translational modifications in microarray or whole-cell based formats. The success of this project will lead to a major technological breakthrough in proteomics research and an instrument that can observe the interaction of drugs with proteins and cells in their native state.
