Structure-based rational design of beta-hairpin peptides from discontinuous epitopes of cluster of differentiation 2 (CD2) protein to modulate cell adhesion interaction.

Modulation or inhibition of interaction of cluster of differentiation (CD) adhesion molecules CD2-CD58 has been shown to be therapeutically useful. The analysis of the crystal structure of CD2 complexed with CD58 was carried out to define the epitopes that are important for the interaction of the two proteins. The crystal structure of CD2 indicated that the interaction surface of CD2 with CD58 has two beta-strand structures (F and C strands) with charged residues. On the basis of the crystal structure of the complex CD2-CD58, we have designed beta-hairpin peptides from the beta-strand region of CD2 by conjugating the discontinuous sequences in the protein. The peptides were modeled by molecular dynamics simulation, and their inhibitory activities were evaluated in vitro using two heterotypic cell adhesion assays, E-rosetting and lymphocyte-epithelial cell adhesion assays. Results indicated that 12- and 14-residue conjugate cyclic peptides cKS12 and cDD14 exhibited 60% and 50% inhibition activity, respectively, at 90 microM.