Rb9 peptide

Rb9 peptide

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

H-CARGETARATFAYWGQGC-NH2

H-Cys-Ala-Arg-Gly-Glu-Thr-Ala-Arg-Ala-Thr-Phe-Ala-Tyr-Trp-Gly-Gln-Gly-Cys-NH2

18

95.35%

C₈₃H₁₂₃N₂₇O₂₄S₂

1947.15

Synthetic

Powder

Peptide Rb9 is a cyclic peptide derived from the VHCDR3 of a humanized monoclonal antibody called RebmAb 200. It reacts with an epitope in the sodium-phosphate transporter NaPi2b and displays bio-reactivity independent of mAb specificity. The peptide was synthesized by Peptide 2.0 and modifications included amidation at the C terminus (NH2) and cyclization (C-C, disulfide bridge). It has been shown to have immunomodulatory protective effects in a metastatic melanoma setting and has been tested against syngeneic CT26 colon and Panc02 pancreatic cancer cells grafted subcutaneously in C57Bl/6 mice. It activates murine or human dendritic cells and enhances the immune response against cancer cells. The peptide has been studied for its anti-tumor protective effects against metastatic melanoma and has shown potential as a new anticancer drug.

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

• Machado FC, Girola N, Maia VSC, Bergami-Santos PC, Morais AS, Azevedo RA, Figueiredo CR, Barbuto JAM, Travassos LR. Immunomodulatory Protective Effects of Rb9 Cyclic-Peptide in a Metastatic Melanoma Setting and the Involvement of Dendritic Cells. Front Immunol. 2020 Jan 15;10:3122. doi: 10.3389/fimmu.2019.03122. PMID: 32010152; PMCID: PMC6974543.

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.