Fig. 3. Cyclic peptides exhibited enhanced resistance towards proteolytic degradation. (a) Chemical structures of cyclic peptides 2j′ and 2p. (b) Proteolytic degradation assay of stapled peptides 2j′ and 2p and their linear counterparts 1g and 1m. Assay conditions: 50 mM Tris buffer, pH 7.4, 50 μM peptide substrates, 0.1 mg ml^–1 protease AspN or trypsin, at 25 °C.