Cyclic Analogues of Proline-Rich Protein Fragments : part III. Synthesis of New Analogues, Conformational Studies and Evaluation of Immunotropic Activity

The immunotropic activity of peptides studied evaluated in the murine system indicated that they are as active as the linear precursor in the resistance to hydrocortisone, but did not show activity in the human system. As reported previously, similar immunotropic profiles were observed in the case of two cyclic analogues. Superposition of most representative conformations of all four peptides in the fragment mentioned above (RMSD of A carbons is0.86 A) leads to the conclusion that this hexapeptide segment might be considered as bioactive.