Rational Design And Functional Evaluation Of A Novel HIL-6 Antagonist Peptide With High Affinity

Human interleukin-6 (hIL-6) is a multifunctional cytokine involved in the maintenance and progression of several diseases. The results, derived from abundant molecular biological mutant experiments and crystal diffraction analysis, became not only the base of determining structural model and functional binding epitopes between hIL-6 and its receptor at molecular level, but also the model of designing molecular antagonists of hIL-6. The present work was to design a novel hIL-6 antagonist peptide with high affinity on the basis of the selected important functional epitopes (i.e. the AB-loop and C-terminal of helix-A, D in hIL-6) and evaluated its biological activities in both XG-7 and Ml cells.(1) A novel hIL-6 antagonist peptide was designed rationally based on the complex crystal structure of hIL-6/hIL-6RBased on the complex crystal structure of hIL-6/hIL-6R, the important binding epitopes of hIL-6 and hIL-6R was determined. Aimed at the AB loop and C-terminal of A, D-helix of hIL-6, the antagonist peptide (named PT) possessed potential bioactivity of hIL-6 was designed using computer-guided design method. The theoretical studies showed that PT offered a practical means of imposing long-term blockade of hBL-6 activity and possessed very high affinity to hIL-6R in vivo.(2) Expression, purification function on hIL-6R and its mutant. The competingbinding activity was analyzed between PT and hIL-6 with hIL-6RUsing cDNA-514 as a template, the two genes of hEL-6R-EC05 (the...