5 research outputs found
In Vitro Selection of Macrocyclic α/β<sup>3</sup>‑Peptides against Human EGFR
Here, we report ribosomal
construction of thioether-macrocyclic
α/β3-peptide libraries in which β-homoglycine,
β-homoalanine, β-homophenylglycine, and β-homoglutamine
are introduced by genetic code reprogramming. The libraries were applied
to the RaPID (Random nonstandard Peptides Integrated Discovery) selection
against human EGFR to obtain PPI (protein–protein interaction)
inhibitors. The resulting peptides contained up to five β3-amino acid (β3AA) residues and exhibited
outstanding binding affinity, PPI inhibitory activity, and proteolytic
stability, which were attributed to the β3AAs included
in the peptides. This showcase work has demonstrated that the use
of such β3AAs enhances the drug-like properties of
peptides, providing a unique platform for the discovery of de novo
macrocycles against a protein of interest
In Vitro Selection of Macrocyclic α/β<sup>3</sup>‑Peptides against Human EGFR
Here, we report ribosomal
construction of thioether-macrocyclic
α/β3-peptide libraries in which β-homoglycine,
β-homoalanine, β-homophenylglycine, and β-homoglutamine
are introduced by genetic code reprogramming. The libraries were applied
to the RaPID (Random nonstandard Peptides Integrated Discovery) selection
against human EGFR to obtain PPI (protein–protein interaction)
inhibitors. The resulting peptides contained up to five β3-amino acid (β3AA) residues and exhibited
outstanding binding affinity, PPI inhibitory activity, and proteolytic
stability, which were attributed to the β3AAs included
in the peptides. This showcase work has demonstrated that the use
of such β3AAs enhances the drug-like properties of
peptides, providing a unique platform for the discovery of de novo
macrocycles against a protein of interest
In Vitro Selection of Macrocyclic α/β<sup>3</sup>‑Peptides against Human EGFR
Here, we report ribosomal
construction of thioether-macrocyclic
α/β3-peptide libraries in which β-homoglycine,
β-homoalanine, β-homophenylglycine, and β-homoglutamine
are introduced by genetic code reprogramming. The libraries were applied
to the RaPID (Random nonstandard Peptides Integrated Discovery) selection
against human EGFR to obtain PPI (protein–protein interaction)
inhibitors. The resulting peptides contained up to five β3-amino acid (β3AA) residues and exhibited
outstanding binding affinity, PPI inhibitory activity, and proteolytic
stability, which were attributed to the β3AAs included
in the peptides. This showcase work has demonstrated that the use
of such β3AAs enhances the drug-like properties of
peptides, providing a unique platform for the discovery of de novo
macrocycles against a protein of interest
Efficient siRNA Delivery by Lipid Nanoparticles Modified with a Nonstandard Macrocyclic Peptide for EpCAM-Targeting
The
development of a specific, effective method for the delivery
of therapeutics including small molecules and nucleic acids to tumor
tissue remains to be solved. Numerous types of lipid nanoparticles
(LNPs) have been developed in attempts to achieve this goal. However,
LNPs are probably not taken up by target cells because cancer-targeting
LNPs are typically modified with poly(ethylene glycol) (PEG), which
inhibits the cellular uptake of LNPs, to passively accumulate in tumor
tissue via the enhanced permeability and retention (EPR) effect. It
would clearly be important to develop a LNP with both a prolonged
circulation and cancer-specific efficient uptake for use in an innovative
nanodrug delivery system. Herein, we assessed the effect of nonstandard
macrocyclic peptides against the epithelial cell adhesion molecule
(EpCAM) Epi-1, which was discovered by a random nonstandard peptides
integrated discovery (RaPID) system, on the cellular uptake and therapeutics
delivery of LNPs. A liposomal siRNA delivery system (MEND) was modified
with an Epi-1 lipid-derivative (EpCAM-targeting MEND; ET-MEND). The
resulting ET-MEND showed a more than 27-fold increase in cellular
uptake in EpCAM-positive cell lines. In the case of negative cells,
cellular uptake and the efficiency of the ET-MEND for delivering therapeutics
were comparable with those of nonmodified MEND. In addition, when
systemically injected, the ET-MEND successfully inhibited gene expression
in the tumor tissue at a dose of 0.5 mg siRNA/kg without any obvious
toxicity. These results suggest that a combination of a specific peptide
ligand can be used to identify a RaPID system and that the use of
such a MEND for liposomal drug delivery has the potential for use
in developing a system for the efficacious delivery of pharmaceuticals
to various cancer cells
Highly selective inhibition of histone demethylases by de novo macrocyclic peptides.
The JmjC histone demethylases (KDMs) are linked to tumour cell proliferation and are current cancer targets; however, very few highly selective inhibitors for these are available. Here we report cyclic peptide inhibitors of the KDM4A-C with selectivity over other KDMs/2OG oxygenases, including closely related KDM4D/E isoforms. Crystal structures and biochemical analyses of one of the inhibitors (CP2) with KDM4A reveals that CP2 binds differently to, but competes with, histone substrates in the active site. Substitution of the active site binding arginine of CP2 to N-ɛ-trimethyl-lysine or methylated arginine results in cyclic peptide substrates, indicating that KDM4s may act on non-histone substrates. Targeted modifications to CP2 based on crystallographic and mass spectrometry analyses results in variants with greater proteolytic robustness. Peptide dosing in cells manifests KDM4A target stabilization. Although further development is required to optimize cellular activity, the results reveal the feasibility of highly selective non-metal chelating, substrate-competitive inhibitors of the JmjC KDMs