HFRW peptide

HFRW peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

Palmitoyl-HFRW-NH2

Palmitoyl-His-Phe-Arg-Trp-NH2

4

95.3%

C₄₈H₇₁N₁₁O₅

882.15

Synthetic

Powder

HFRW is a conserved receptor-binding motif found in the a-MSH unit of the adrenocorticotropic hormone (ACTH). It is important for the activation of the MC2R receptor, which is involved in signaling. The HFRW motif, along with the KKRRP sequence at the a-MSHCLIP interface, is required for the activation of MC2R. Processing of ACTH by PC2 to a-MSH specifically abolishes MC2R signaling. The CLIP sequence of ACTH also has a stabilizing effect on plasma stability, although it is weaker compared to the C-terminal orphan poly-Ser sequence of c3-MSH. The C-terminal sequences of both ACTH and c3-MSH contribute to plasma stability, with the poly-Ser sequence of c3-MSH significantly prolonging plasma half-life and reducing degradation.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Löw K, Roulin A, Kunz S. A proopiomelanocortin-derived peptide sequence enhances plasma stability of peptide drugs. FEBS Lett. 2020 Sep;594(17):2840-2866. doi: 10.1002/1873-3468.13855. Epub 2020 Jun 27. PMID: 32506501.

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.