Determination of Binding Sites of Cadherin Peptides on the EC1 domain of E-cadherin using NMR Spectroscopy

Abstract

The objective of this work is to evaluate the binding mechanisms of synthetic cadherin peptides (ADTC7, ADTC9 and cHAVc3) to the EC1 domain of human E-cadherin. The binding sites of these peptides to the EC1 domain were determined by titrating the 15N-labeled EC1 domain with each peptide. The changes in the 1H,15N-HSQC NMR spectra were observed upon peptide titration. The AutoDock Vina molecular modeling program was also used to predict the binding sites of each cadherin peptide on the EC1 domain. NMR data confirmed that there are three potential binding sites of ADTC7 on the EC1 domain; these binding sites are around residues I53/V48, D103, and G115. The two potential binding sites of ADTC9 peptide are around I4 and I53/V48 residues of EC1. The NMR data showed that ADTC7 peptide has higher binding affinity to the EC1 domain than ADTC9 peptide. For cHAVc3, it binds selectively to at the D103 residue on EC1. AutoDock Vina studies confirm some of the binding sites found by NMR studies. In the future, a more detail study will be conducted to evaluate the effect of peptide binding on the dynamics properties of the EC1 domain.