From Proteopediaproteopedia link
Structure-guided design of alpha-amino acid-derived Pin1 inhibitors
[PIN1_HUMAN] Essential PPIase that regulates mitosis presumably by interacting with NIMA and attenuating its mitosis-promoting activity. Displays a preference for an acidic residue N-terminal to the isomerized proline bond. Catalyzes pSer/Thr-Pro cis/trans isomerizations. Down-regulates kinase activity of BTK. Can transactivate multiple oncogenes and induce centrosome amplification, chromosome instability and cell transformation. Required for the efficient dephosphorylation and recycling of RAF1 after mitogen activation.  
Publication Abstract from PubMed
The peptidyl prolyl cis/trans isomerase Pin1 is a promising molecular target for anti-cancer therapeutics. Here we report the structure-guided evolution of an indole 2-carboxylic acid fragment hit into a series of alpha-benzimidazolyl-substituted amino acids. Examples inhibited Pin1 activity with IC(50) <100nM, but were inactive on cells. Replacement of the benzimidazole ring with a naphthyl group resulted in a 10-50-fold loss in ligand potency, but these examples downregulated biomarkers of Pin1 activity and blocked proliferation of PC3 cells.
Structure-guided design of alpha-amino acid-derived Pin1 inhibitors.,Potter AJ, Ray S, Gueritz L, Nunns CL, Bryant CJ, Scrace SF, Matassova N, Baker L, Dokurno P, Robinson DA, Surgenor AE, Davis B, Murray JB, Richardson CM, Moore JD Bioorg Med Chem Lett. 2010 Jan 15;20(2):586-90. Epub 2009 Nov 22. PMID:19969456
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.