| Identification and Rational Redesign of Peptide Ligands to CRIP1, a Novel Biomarker for Cancers | ||
| Adrian W.R. Serohijos1, Jihua Hao2, Dennis C. Sgroi3, James P. Basilion2 and Nikolay V. Dokholyan4, (1)Biochemistry and Biophysics Dept./Physics and Astronomy Dept., University of North Carolina at Chapel Hill, Chapel Hill, NC, (2)Biomedical Engineering and Radiology, Case Western Reserve University, Cleveland, OH, (3)Department of Pathology, Harvard Medical School, Charlestown, MA, (4)Biochemistry and Biophysics Dept./Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC Cysteine-rich intestinal protein one (CRIP1) has been identified as a novel marker for early detection of cancers. Here we report on the use of phage display in combination with molecular modeling to identify a high-affinity ligand for CRIP1. Panning experiments using a circularized C7C phage library yielded several consensus sequences with modest binding affinity to purified CRIP1. Two sequence motifs, A1 and B5, having the highest affinity for CRIP1, were chosen for further study. Using peptide structure information and the NMR structure of CRIP1, the higher affinity A1 peptide was computationally redesigned yielding a novel peptide, A1M, whose affinity was predicted to be much improved. Synthesis of the peptide and saturation and competitive binding studies demonstrated approximately a 10-28 fold improvement in the affinity of A1M compared to either A1 or B5 peptides. These techniques have broad application to the design of novel ligand peptides. Extended Abstract Status: Not Uploaded | ||