RP-832c peptide

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

Peptide RP-832c is a novel synthetic analogue of a naturally occurring Host Defense Peptide (HDP), designed to target the CD206 receptor on M2-polarized macrophages. This peptide plays a crucial role in mediating innate immune responses and has shown promising results in reducing pro-fibrotic cytokines in various models of lung fibrosis.

Activated M2-polarized macrophages are known drivers of pulmonary fibrosis in conditions like Idiopathic Pulmonary Fibrosis (IPF). RP-832c binds selectively to the CD206 receptor on these macrophages, leading to a time-dependent decrease in CD206 expression and an increase in M1-macrophage markers such as TNF-α. This action mechanism suggests that RP-832c can modulate macrophage activation states, shifting them from a pro-fibrotic M2-like phenotype to a potentially less harmful M1-like phenotype.

The efficacy of RP-832c has been tested in vitro using bone marrow-derived macrophages (BMDM) and in vivo using a murine model of bleomycin (BLM)-induced early-stage pulmonary fibrosis. In these models, RP-832c demonstrated a significant reduction in fibrosis in a dose-dependent manner, decreased expression of pro-fibrotic markers like CD206, TGF-β1, α-SMA, and inflammatory cytokines such as TNF-α, IL-6, IL-10, IFN-γ, CXCL1/2. Moreover, RP-832c's effects on reducing lung fibrosis were comparable or even superior to FDA-approved drugs like Nintedanib and Pirfenidone, without exhibiting any significant toxicity at the tested doses.

RP-832c represents a potential new avenue for treating pulmonary fibrosis, targeting the activated M2-like macrophages that are central to the disease's progression. Its ability to modify macrophage phenotype and reduce fibrosis without significant toxicity highlights its therapeutic potential for patients with pulmonary fibrosis

• Ghebremedhin A, Salam AB, Adu-Addai B, Noonan S, Stratton R, Ahmed MSU, Khantwal C, Martin GR, Lin H, Andrews C, Karanam B, Rudloff U, Lopez H, Jaynes J, Yates C. A Novel CD206 Targeting Peptide Inhibits Bleomycin-Induced Pulmonary Fibrosis in Mice. Cells. 2023 Apr 26;12(9):1254. doi: 10.3390/cells12091254. PMID: 37174654; PMCID: PMC10177262.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.