Synthesis of cell-permeable stapled BH3 peptide-based Mcl-1 inhibitors containing simple aryl and vinylaryl cross-linkers

Abstract

We report the synthesis of a series of distance-matching aryl and vinylaryl cross-linkers for constructing stapled peptides containing cysteines at i,i+7 positions. Langevin dynamics simulation studies helped to classify these cross-linkers into two categories: the rigid cross-linkers with narrower S-S distance distribution and the flexible cross-linkers with wider S-S distance distribution. The stapled Noxa BH3 peptides with the flexible distance-matching cross-linkers gave the highest degree of helicity as well as the most potent inhibitory activity against Mcl-1. However, the stapled peptides with the highest hydrophobicity showed the most efficient cellular uptake. Together, this work illustrates the divergent nature of binding affinity and cellular uptake, and the vital importance of choosing appropriate cross-linkers in constructing stapled peptides with the drug-like properties.

Avoiding drug resistance through extended drug target interfaces: a case for stapled peptides

“…Stapled peptides targeting numerous intracellular targets have been described, with many employing an all-hydrocarbon olefin stapling moiety [5]. Alternative stapling chemistries have also been reported [6, 7]. …”

Design of Potent and Proteolytically Stable Oxyntomodulin Analogs

“…(26) To our satisfaction, cross-linked peptide 11 showed even more potent agonist activities in dual activation of GLP-1R and GCGR with EC 50 values of 0.07 nM and 0.18 nM, respectively (Figure S2). …”

“…(29) Assuming the 3 10 –helix represents an unproductive conformation, the lack of 3 10 –helix from the conformational ensemble may be beneficial to the receptor binding, although other factors other than secondary structures may also affect the binding. (26, 30) For example, despite having similar CD spectra, peptide 11 has 3–4 fold greater efficacy in receptor activation than peptide 9 (Table 1). This difference can be explained by the presence of the pyridyl nitrogen in the Bpy structure, which may form a hydrogen bond with Glu-128 of the extracellular domain of GLP-1R (Figure S4).…”

Stapling peptides using cysteine crosslinking

“…For instance, in an α‐helical peptide, residues located at the ( i , i + 4), ( i , i + 7) or ( i , i + 11) positions reside on the same face of the helix and are therefore strategic points to place two cysteines (Figure ) . In model helical peptides, the gap between the SH group of the cysteines was estimated to span between 9‐13 Å (median 11.2 Å) when in ( i , i + 7) positions and 14‐20 Å in ( i , i +11) positions, encouraging the use of long crosslinkers of matching length. For non‐α‐helical peptides featuring cyclic loops, the number of residues between the two cysteines may be altered to create rings of differing sizes, conformations and presenting epitopes (Figure ).…”