Chemical probes for imaging biological processes

In the last twenty years chemical probes have united Chemistry and Biology in an effort to illuminate biological processes at the cellular level as well as in intact organisms. These chemical probes are developed as a new generation of probes to amplify a specific cellular signal and only be detected when an event of interest occurs. Fluorescent chemical probes and magnetic resonance imaging contrast agents in particular have generated much interest from researchers, as the techniques that they are used with are easily accessible, sensitive and applicable to both fields in answering a wide variety of problems.;This thesis presents the development of fluorescent probes for imaging protein tyrosine phosphatase activity. The probes are peptide based and incorporate a fluorescent amino acid, that is a phosphotyrosine mimic, specific for protein tyrosine phosphatases and has excellent spectral properties. The probes were successfully used to determine kinetic parameters of protein tyrosine phosphatases and also detect enzyme activity in cells. The design and ligand synthesis for potential zinc selective magnetic resonance imaging contrast agent is also presented. The ligand is a polyazamacrocycle tricarboxylic acid that is monofunctionalized with zinc selective side arm. Theoretical studies of the available surface area on the gadolinium atom in the metal complex of the ligand, reveal that upon zinc binding, there is enough area for two water molecules to bind. Those results indicate that the gadolinium complex of the ligand will be an excellent contrast agent for zinc imaging.