Q11 peptide

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

Batch to batch variation of the purity

• Q11 polypeptide (QQKFQFQFEQQ) is a beta-sheet fibrillizing peptide. This polypeptide is capable of self-assembling into fibrils and forming hydrogels, which can serve as matrices for various cell types. It allows for the incorporation of ligands such as RGDS and IKVAV through co-assembly with other peptides. The ligand display can be adjusted simply by mixing different peptides in solution and inducing gelation.
• Q11-based gels have shown minimal cytotoxicity and immunogenicity, making them suitable for in vitro and potentially in vivo applications. They also exhibit stable fibrillization and mechanical properties that are minimally affected by ligand incorporation, enabling independent control over ligand presentation and gel mechanics. Overall, Q11 polypeptide offers a modular and tunable platform for designing biomaterials that can direct cellular responses and has potential uses in areas such as regenerative medicine and cell culture.

• Jung JP, Nagaraj AK, Fox EK, Rudra JS, Devgun JM, Collier JH. Co-assembling peptides as defined matrices for endothelial cells. Biomaterials. 2009 Apr;30(12):2400-10. doi: 10.1016/j.biomaterials.2009.01.033. Epub 2009 Feb 8. PMID: 19203790; PMCID: PMC2677558.

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.