Stapling peptides using cysteine crosslinking

Abstract

Stapled peptides are an emerging class of cyclic peptide molecules with enhanced biophysical properties such as conformational and proteolytic stability, cellular uptake and elevated binding affinity and specificity for their biological targets. Among the limited number of chemistries available for their synthesis, the cysteine-based stapling strategy has received considerable development in the last few years driven by facile access from cysteine-functionalized peptide precursors. Here we present some recent advances in peptide and protein stapling where the side-chains of cysteine residues are covalently connected with a range of different crosslinkers affording bisthioether macrocyclic peptides of varying topology and biophysical properties. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 843-852, 2016.

Tuning the Binding Affinity and Selectivity of Perfluoroaryl‐Stapled Peptides by Cysteine‐Editing

“…Most often, however, cysteine thiol residues have provided an excellent handle for peptide stapling, driven mainly by the ease and relatively low cost of obtaining the linear pre‐stapled peptide. This topic has been recently reviewed by Fairlie . Examples of thiol cross‐linking include the use of dibromomaleimide, dichloroacetone, 1‐,4‐dichlorotetrazine, 1,2,4,5‐tetrabromodurene, α,α′‐dibromo‐ m ‐xylene, trans ‐1,4‐dibromo‐2‐butene and cis ‐1,4‐dichloro‐2‐butene and perfluoroaryl reagents .…”

“…This topic has been recently reviewed by Fairlie. [16] Examples of thiol cross-linking include the use of dibromomaleimide, [17] dichloroacetone, [18] 1-,4-dichlorotetrazine, [19] 1,2,4,5-tetrabromodurene, [20] a,a'-dibromo-m-xylene, [21] trans-1,4-dibromo-2butene and cis-1,4-dichloro-2-butene [22] and perfluoroaryl reagents. [23] Although significant attention has focussedo nt he natureo ft he cross-linking electrophile, comparatively little, if any,a ttention has focussed on the cysteine residues, with the single exceptiono fi ntroducing homocysteine.…”

Development of cell‐penetrating peptide‐based drug leads to inhibit MDMX:p53 and MDM2:p53 interactions

“…Various stapling strategies (e.g., lactam bridges, carbon‐carbon, triazole, thioether, disulfide bonds) can be used to constrain peptides into a helical conformation but for the stapled peptides to be active against cancer cells, in addition to inhibiting MDM2:p53 and/or MDMX:p53 interactions, they must be able to cross the cell membrane and reach the cytosol where these proteins are located. Promising results have been achieved and some p53‐derived stapled peptides were shown to enter into cells and activate p53‐dependent apoptosis in vivo.…”

Tuning Sulfur Oxidation States on Thioether‐Bridged Peptide Macrocycles for Modulation of Protein Interactions

“…Prior to evaluating effects of thioether oxidation on molecular recognition sites in proteins, we first sought to evaluate how modulations of the structure and oxidation state of the sulfur‐bridged side chains could affect the physiochemical properties of peptides. By incorporating a bis‐thioether constraint to enforce α‐helicity in a sequence‐defined manner, helicity and polarity are evaluated (Figure A) . Oxidation of thioether groups into sulfones and sulfoxides provides a facile method for increasing polarity of otherwise hydrophobic peptides .…”