R18 peptide

R18 peptide

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

H-PHCVPRDLSWLDLEANMCLP-OH

H-Pro-His-Cys-Val-Pro-Arg-Asp-Leu-Ser-Trp-Leu-Asp-Leu-Glu-Ala-Asn-Met-Cys-Leu-Pro-OH

20

95.95%

C₁₀₁H₁₅₇N₂₇O₂₉S₃

2309.67

Synthetic

Powder

R18, also known as R18 peptide is an antagonist of 14.3.3 proteins, a family of conserved regulatory molecules that have the ability to bind a multitude of functionally diverse signaling proteins, with a KD of approximately 80 nM. R18 competitively inhibits 14.3.3 ligand interactions without requiring phosphorylation and can block the ability of 14.3.3 to bind to target proteins such as Raf-1, Bad, ASK1 and exoenzyme S.

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

• Wang et al (1999) Isolation of high-affinity peptide antagonists of 14.3.3 proteins by phage display. Biochemistry 38 12499 PMID: 10493820
• Masters et al (2002) Survival-promoting functions of 14.3.3 proteins. Biochem.Soc.Transactions 30 360 PMID: 12196095
• De Vries-van Leeuwen et al (2013) ERα activation is controlled by 14-3-3 proteins. Proc. Nat. Acad. Sci. 110(22) 8894 DOI: 10.1073/pnas.1220809110

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.