L17E 

L17E is an attenuated cationic amphiphilic lytic (ACAL) peptide that can be used to deliver a variety of macromolecules, including proteins, antibodies, and DNA nanostructures. L17E inserts and cleaves the membrane structure through electrostatic interaction, enabling intracellular escape. The efficiency of L17E-mediated delivery is strongly correlated with the expression level of KCNN4 (the gene encoding the calcium-activated potassium channel KCa3.1). L17E also promotes the cellular uptake of macromolecules by inducing micropinocytosis. L17E can be further optimized and improved through dimerization strategies and in combination with other delivery systems, such as nuclear localization signal peptides and cell membrane-coated nanoparticles^{[1][2][3][4][5][6]}.

L17E (40-80 μM) suppresses TS5-p45 translocation to the nucleus in HUVECs by disrupting the integrity of the late endosome (LE) membrane^[1].
L17E (50-100 μM, 25 h) eliminates the pro-apoptotic activity of TS5-p45 (TS5-p45 must enter the cell nucleus in order to trigger the apoptotic process) in HUVECs^[1].
L17E causes approximately 50% of the cells to exhibit strong cytoplasmic signals in Hela cells and its ability to lyse negatively charged membranes is much stronger than that on neutral membranes with no significant pH dependence^[2].
L17E (40μM, 1-24 h) exhibits almost 90% cell viability when treated in serum-free medium for one hour or serum-supplemented medium for 24 hours^[2][3].
L17E (40 μM, 7 h) efficiently delivers the ribosome inactivating protein (Saporin), resulting in approximately 80% Hela cell death; while without it, the cell death rate is only approximately 15%^[2].
L17E (40 μM, 25 h) delivers the Cre recombinase and initiates the expression of EGFP in Hela cells^[2].
L17E (40 μM, 1.5 h) delivers anti-His₆-IgG to the cytoplasmic side and successfully bound to the intracellular target in Hela cells^[2].
L17E (40 μM, 0.5 h) with anti-GR antibody treatment is able to significantly inhibit the upregulation of the MT1E gene induced by Dexamethasone (Dex) (HY-14648G)^[2].
L17E (40 μM, 49 h) enhances the efficacy of exosome-mediated intracellular delivery in Hela cells^[2].
L17E (20-40 μM, 1 h) enhances the internalization of Dex by inducing macropinocytosis, and achieves cytoplasmic release by specifically lysing the endosomal membrane^[2].
L17E coating enables efficient endosomal release of tetrahedral DNA frameworks (TDFs) in RAW264.7 cells^[4].
L17E coating substantially enhances the stability of TDFs and improves their uptake efficiency into RAW264.7 cells through endocytosis and macropinocytosis^[4].
L17E (12 h)-coated TDF to deliver osteogenic growth peptide (OGF) exerts powerful antioxidant and anti-inflammatory functions within the RAW264.7 cells^[4].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

L17E-TDF-OGP (situ injection, single dose) inhibits efficiently periodontitis in mice^[4].
DNase@BSNP-NLS/L17E-M (with L17E encapsulated) (10 mg/mL, i.v., once every two days for 5 times) homologously deliveres functional proteins to cancer cell nuclei in Hela-xenografted mice and exhibits significant anti-tumor properties^[5].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

2859.42

C₁₃₄H₂₂₀N₃₈O₃₁

1898254-09-5

Solid

White to off-white

Ile-Trp-Leu-Thr-Ala-Leu-Lys-Phe-Leu-Gly-Lys-His-Ala-Ala-Lys-His-Glu-Ala-Lys-Gln-Gln-Leu-Ser-Lys-Leu-NH2

IWLTALKFLGKHAAKHEAKQQLSKL-NH2

Room temperature in continental US; may vary elsewhere.

Sealed storage, away from moisture

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Dogan Can Kirman, et al. Cell surface nucleolin is a novel ADAMTS5 receptor mediating endothelial cell apoptosis. Cell Death Dis. 2022 Feb 23;13(2):172.  [Content Brief]

  [2]. Akishiba M, et al. Cytosolic antibody delivery by lipid-sensitive endosomolytic peptide. Nat Chem. 2017 Aug;9(8):751-761.  [Content Brief]

  [3]. Nomura Y, et al. Improved cytosolic delivery of macromolecules through dimerization of attenuated lytic peptides. Bioorg Med Chem Lett. 2020 Sep 1;30(17):127362.  [Content Brief]

  [4]. He, Jinjun, et al. Coating tetrahedral DNA framework with endosomolytic peptides for improved stability and cytosolic delivery. Advanced Sensor and Energy Materials 3.2 (2024): 100098.

  [5]. Du W, et al. Biodegradable silica nanocapsules enable efficient nuclear-targeted delivery of native proteins for cancer therapy. Biomaterials. 2023 Mar;294:122000.  [Content Brief]

  [6]. Kuriyama M, et al. KCNN4 as a genomic determinant of cytosolic delivery by the attenuated cationic lytic peptide L17E. Mol Ther. 2025 Feb 5;33(2):595-614.  [Content Brief]