LSKL peptide

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

Batch to batch variation of the purity

The LSKL peptide, composed of the amino acid sequence leucine-serine-lysine-leucine, functions as an inhibitor of thrombospondin-1 (TSP-1)-mediated activation of transforming growth factor-beta (TGF-β) signaling. TSP-1 is a matricellular protein known to convert latent TGF-β into its active form by binding to latency-associated peptide (LAP). The LSKL peptide competitively blocks this interaction, thereby suppressing TGF-β-Smad signal transduction. Experimental studies demonstrate that LSKL administration attenuates Smad2 phosphorylation and upregulates downstream targets such as Myc, cyclin D1, and cyclin A2, which are associated with accelerated cell cycle progression in hepatocytes.

In vivo analyses reveal that LSKL peptide administration does not alter TSP-1 expression levels but effectively disrupts TSP-1-dependent TGF-β activation. This transient inhibition promotes hepatocyte proliferation, particularly during the early phases of liver regeneration, without inducing adverse effects in other organs. The peptide's mechanism highlights its role as a modulator of extracellular TGF-β bioavailability, offering insights into its potential applications in regulating tissue repair processes.

• Kuroki H, Hayashi H, Nakagawa S, Sakamoto K, Higashi T, Nitta H, Hashimoto D, Chikamoto A, Beppu T, Baba H. Effect of LSKL peptide on thrombospondin 1-mediated transforming growth factor β signal activation and liver regeneration after hepatectomy in an experimental model. Br J Surg. 2015 Jun;102(7):813-25. doi: 10.1002/bjs.9765. Epub 2015 Apr 13. PMID: 25866938; PMCID: PMC4654236.

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.