ABSTRACT
Interleukin-6 (IL-6) is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman's Disease (CD) and rheumatoid arthritis (RA). Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R)/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs) directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs) directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK) profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG) moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA) and C-reactive protein (CRP). This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology.
Subject(s)
Interleukin-6/antagonists & inhibitors , Peptides/pharmacology , Amino Acid Sequence , Animals , Drug Design , Half-Life , Humans , Hybridomas , Interleukin-6/chemistry , Interleukin-6/metabolism , Macaca fascicularis , Male , Mice , Mice, Inbred BALB C , Mice, Inbred ICR , Models, Molecular , Molecular Sequence Data , Peptide Library , Peptides/chemistry , Peptides/metabolism , Protein Conformation , Random Allocation , Rats , Rats, Sprague-Dawley , Receptors, Interleukin-6/chemistry , Recombinant Proteins/pharmacology , STAT3 Transcription Factor/metabolism , Structure-Activity Relationship , U937 CellsABSTRACT
Reversible tetrapeptide-based compounds have been shown to effectively inhibit the hepatitis C virus NS3.4A protease. Inhibition of viral replicon RNA production in Huh-7 cells has also been demonstrated. We show herein that the inclusion of hydrogen bond donors on the P4 capping group of tetrapeptide-based inhibitors result in increased binding potency to the NS3.4A protease. The capping groups also impart significant effects on the pharmacokinetic profile of these inhibitors.
Subject(s)
Antiviral Agents/pharmacokinetics , Hepacivirus/drug effects , Protease Inhibitors/pharmacokinetics , Viral Nonstructural Proteins/antagonists & inhibitors , Virus Replication/drug effects , Animals , Antiviral Agents/chemical synthesis , Binding Sites , Cell Line , Crystallography, X-Ray , Drug Design , Hepacivirus/enzymology , Hydrogen Bonding , Mice , Microbial Sensitivity Tests , Oligopeptides/antagonists & inhibitors , Protease Inhibitors/chemical synthesis , Structure-Activity Relationship , Virus Replication/physiologyABSTRACT
We recently described the identification of an optimized alpha-ketoamide warhead for our series of HCV NS3.4A inhibitors. We report herein a series of HCV protease inhibitors incorporating 3-alkyl-substituted prolines in P(2). These compounds show exceptional enzymatic and cellular potency given their relatively small size. The marked enhancement of activity of these 3-substituted proline derivatives relative to previously reported 4-hydroxyproline derivatives constitutes additional evidence for the importance of the S(2) binding pocket as the defining pharmacophore for inhibition of the NS3.4A enzyme.
Subject(s)
Carrier Proteins/antagonists & inhibitors , Oligopeptides/pharmacology , Proline/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Proteins/antagonists & inhibitors , Hepatitis C/enzymology , Intracellular Signaling Peptides and Proteins , Models, Molecular , Molecular Structure , Oligopeptides/chemical synthesis , Oligopeptides/chemistry , Proline/chemical synthesis , Proline/chemistry , Structure-Activity RelationshipABSTRACT
Tetrapeptide-based peptidomimetic compounds have been shown to effectively inhibit the hepatitis C virus NS3.4A protease without the need of a charged functionality. An aldehyde is used as a prototype reversible electrophilic warhead. The SAR of the P1 and P2 inhibitor positions is discussed.
