Date of Award


Document Type

Open Access Thesis


College of Pharmacy


Pharmaceutical Science

First Advisor

Campbell McInnes

Second Advisor

James Chapman


CDK2/cyclin A and CDK4/cyclin D1 are proven targets for cancer drug discovery. The development of novel CDK inhibitors, with high selectivity, are being investigated by targeting the cyclin binding groove (CBG) located on the cyclin, the regulatory subunit of CDK. The CBG is a shallow area that is involved in signaling and the inhibition of cell cycle CDKs via endogenous tumor suppressors. Currently, non-peptidic inhibitors are being developed based on the recognition amino acid sequence, HAKRRLIF, of the C-terminal peptide sequence of the CDK inhibitor p21WAF1. Computational design and the utilization of non-natural amino acids are being proposed to identify small molecules to replace the C-terminal amino acids (RLIF) via the REPLACE methodology. Such small molecules, known as capping groups, have significant potential for converting the octamer into a more drug-like molecule. The REPLACE methodology has been applied and used to identify novel Ccaps to replace RLIF of the octamer. These Ccaps have IC50 values in the 40-100 μM range against the cell cycle CDK/cyclin complexes of interest. The fragment ligated inhibitory peptides (FLIPs) have been synthesized, coupled with a potent small molecule N-terminal capping group (Ncap), and their binding affinities have been tested using a Fluorescence Polarization (FP) assay. The results reported here enhance the development of a selective, drug-like, cell permeable small molecule CDK cyclin groove inhibitors by generating promising Ccaps and by identifying a novel approach to the designing of potential partial ligand alternatives. Further, these results bring us closer to achieving the ultimate goal of developing a novel class of cancer therapeutics based on cell cycle inhibition through the cyclin dependent kinases.


© 2013, Tracy Perkins