QS-13 peptide

QS-13 peptide

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

Batch to batch variation of the purity

QKISRCQVCVKYS

H-Gln-Lys-Ile-Ser-Arg-Cys-Gln-Val-Cys-Val-Lys-Tyr-Ser-OH

13

95.5%

C₆₅H₁₁₂N₂₀O₁₉S₂

1541.83

Synthetic

Powder

Tetrastatin, a 230 amino acid sequence from collagen IV, was demonstrated to inhibit melanoma progression. The minimal active sequence (QKISRCQVCVKYS: QS-13) could reproduce the anti-tumor effects of whole Tetrastatin in vivo and in vitro on melanoma cell proliferation, migration and invasion. QS-13 binds to SK-MEL-28 melanoma cells through the αvβ3 integrin using blocking antibody and β3 integrin subunit siRNAs strategies. Relevant QS-13 conformations were extracted from molecular dynamics simulations and their interactions with αVβ3 integrin were analyzed by docking experiments to determine the binding areas and the QS-13 amino acids crucial for the binding. The in silico results were confirmed by in vitro experiments. Indeed, QS-13 binding to SK-MEL-28 was dependent on the presence of a disulfide-bound as shown by mass spectroscopy and the binding site on αVβ3 was located in close vicinity to the RGD binding site. QS-13 binding inhibits the FAK/PI3K/Akt pathway, a transduction pathway that is largely involved in tumor cell proliferation and migration. QS-13 peptide binds αvβ3 integrin in a conformation-dependent manner and is a potent antitumor agent that could target cancer cells through αVβ3.

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

• Lambert E, Fuselier E, Ramont L, et al. Conformation-dependent binding of a Tetrastatin peptide to u03b1_vu03b2₃ integrin decreases melanoma progression through FAK/PI₃K/Akt pathway inhibition. Sci Rep. 2018;8(1):9837

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.