[Ala11,D-Leu15]-Orexin B peptide

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

Batch to batch variation of the purity

• Asahi et al (2003) Development of an orexin-2 receptor selective agonist, [Ala11D-Leu15]orexin-B. Bioorg.Med.Chem.Lett. 13 111 PMID: 12467628
• Borgland et al (2008), Orexin B/hypocretin 2 increases glutamatergic transmission to ventral tegmental area neurons. European J. Neuroscience 28 1545 PMID: 18793323
• Staton et al (2018) Orexin 2 receptor stimulation enhances resilience, while orexin 2 inhibition promotes susceptibility, to social stress, anxiety and depression, Neuropharmacology 143 79 PMID: 30240784

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.