Antagonistic effect of disulfide-rich peptide aptamers selected by cDNA display on interleukin-6-dependent cell proliferation

► Disulfide-rich peptide aptamer inhibits IL-6-dependent cell proliferation. ► Disulfide bond of peptide aptamer is essential for its affinity to IL-6R. ► Inhibitory effect of peptide depends on number and pattern of its disulfide bonds.