Abstract
Protein functions and dynamics in living cells can provide important information in biological research and medical diagnosis. The uses of fluorescent probes to study proteins are advantageous, as they allow for fast, high sensitivity, high specificity and ease for observation. In this thesis, I have designed two novel fluorescent probes for SNAP-tag which is an important protein in chemical biology for specific and covalent reaction with probes consisting O6-benzylguanine moiety. The first probe is based on the caged-benzylguanine concept by chemical modification of benzylguanine N-9 position to prevent the reaction of benzylguanine and SNAP-tag. Upon uncaging with the target molecule, the fluorescent dye can then be transferred to the SNAP-tag or MGMT (benzylguanine wild type protein) to emit stronger fluorescence. In the second fluorescent probe, we have successfully developed two near-infrared fluorescent probes based on Nile red and Nile blue, respectively, for fluorescent turn-on labeling of SNAP-tag protein. We have successfully applied these two probes for no-was and highly organelle specific labeling of SNAP-tag proteins in living cells.