De novo design of isopeptide bond-tethered triple-stranded coiled coils with exceptional resistance to unfolding and proteolysis: implication for developing antiviral therapeutics

Abstract

Isopeptide bridge-tethered ultra-stable coiled-coil trimers have been de novo designed as structure-directing auxiliaries to guide HIV-1 gp41 NHR-peptide trimerization.

Site-specific Isopeptide Bridge Tethering of Chimeric gp41 N-terminal Heptad Repeat Helical Trimers for the Treatment of HIV-1 Infection

“…2a ). It relied on thioester-modified trimeric coiled-coil assemblies to juxtapose the acyl donor and acceptor moieties as competent active sites 20 22 . In general, a Glu residue with an allyloxy group (OAll)-modified side chain was placed at the engineered active-site positions within the IZN17 peptide and its derivatives to substitute the original Glu residues.…”

“…In addition, the isopeptide bonds cross the grooves of the N-helix trimer, which may slightly perturb the folding of the N-peptides and C34 and lead to imperfect coiled-coil structures, thus appearing as smeared bands in N-PAGE. The size of the complex formed between (IZ14N24N) 3 and the C34 peptide was further assessed by sedimentation velocity analysis (SVA), which is particularly useful for quantitatively characterizing the behavior of biomolecules in solution 20 . As shown in Fig.…”

“…& Tech. Co. Ltd.) by using a CEM Liberty peptide synthesizer following the general procedure for Fmoc chemistry of solid-phase peptide synthesis as described previously 20 . Briefly, 0.45 M O -benzotriazol-1-yl- N,N,N’,N’ -tetramethyl-uronium hexafluorophosphate (HBTU, GL Biochem (Shanghai) Ltd.) and 2 M diisopropylethylamine (DIEA, Acrose) in DMF solution were used as coupling reagents.…”

“…Ultra-high stability provided by isopeptide bond crosslinks is present in a range of bacterial surface proteins. Inspired by this, we very recently developed an isopeptide bridge-tethering strategy for the stabilization of de novo coiled coils with simple peptide sequences 20 . In the present work, we performed lead optimization based on the scaffold of (CCIZN17) 3 in which isopeptide bonds were incorporated into the IZ motif, a well-folded trimeric coiled coil with an extremely complex chemical environment, to replace the interhelical disulfide at the N-terminus of the chimeric peptide.…”

Folding Topology of a Short Coiled‐Coil Peptide Structure Templated by an Oligonucleotide Triplex

“…In contrast, a relatively large portion of most proteins is responsible for conformational stability . Inspired by Nature, de novo construction of functional man‐made protein mimics from protein subunits and peptide sequences through noncovalent interactions is a research area of strong interest …”