TAT-Gap19 peptide

TAT-Gap19 peptide

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

Batch to batch variation of the purity

H-YGRKKRRQRRRKQIEIKKFK-OH

H-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-Lys-Gln-Ile-Glu-Ile-Lys-Lys-Phe-Lys-OH

20

95.74%

C₁₁₉H₂₁₂N₄₆O₂₆

2703.24

Synthetic

Powder

TAT-Gap19 is a connexin43 (Cx43) hemichannel blocker, with an IC50 of 7 μM and no significant affinity for gap junctions or Panx1 channels. TAT-Gap19 is derived from Gap19, a sequence present on the intracellular cytoplasmic loop domain of Cx43, linked to the HIV-derived TAT internalization sequence to promote membrane permeability, which also allows brain penetration. In mouse models of liver damage, TAT-Gap19 can protect against liver fibrosis accompanied by superoxide dismutase overactivation and reduces production of inflammatory proteins.

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

• Abudara et al (2014) The connexin43 mimetic peptide Gap19 inhibits hemichannels without altering gap junctional communication in astrocytes. Front.Cell.Neurosci. 8 1 PMID: 25374505
• Crespo et al (2018) TAT-Gap19 and Carbenoxolone Alleviate Liver Fibrosis in Mice. Int J Mol Sci. 9(3) 817 PMID: 29534516
• Ramadan (2020) Connexin43 Hemichannel Targeting With TAT-Gap19 Alleviates Radiation-Induced Endothelial Cell Damage. Front Pharmacol. 11 212 PMID: 32210810

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.