LAH4 is an α-helix of an amphipathic peptide antibiotic with potent antimicrobial, nucleic acid transfection and cell penetration activities. LAH4 has high plasmid DNA delivery ability. LAH4 has a strong affinity for anionic lipids in the outer membrane of bacterial membranes.

Physicochemical Properties

Molecular Formula	C132H228N38O27
Molecular Weight	2779.53
CAS #	184776-51-0
Related CAS #	LAH4 TFA
Appearance	Typically exists as solid at room temperature
Density	1.201±0.06 g/cm3(Predicted)
Boiling Point	2489.3±65.0 °C(Predicted)
SMILES	[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](N)CCCCN)(C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](C)C(=O)O)CC1N=CNC=1)CC1N=CNC=1)CC1N=CNC=1)CC1N=CNC=1
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro

In an endosome, LAH4 can encapsulate DNA, bind to the cell surface membrane, and then, when the pH falls, rupture the endosomal membrane[1]. Plasmid DNA transfection capabilities of LAH4 are strong. In vitro delivery of siRNAs into a human cell line can be accomplished effectively by peptides belonging to the LAH4 family[2]. Enhancement of cross presentation of protein antigen by dendritic cells to CD8+ T cells is caused by LAH4's ability to mediate the intracellular delivery of both protein and nucleotide cargo and facilitate protein internalization through mechanisms involving endosomal acidification and processing through the proteasome pathway. The adjuvant action of CpG is further enhanced by LAH4, which enhances CpG internalization and NF-kB activation[3]. Bacillus subtilis and Escherichia coli are two microorganisms that LAH4 is active against. Yet, at bacteriocidal quantities, the peptide does not lyse human red blood cells. When pH 5 is used instead of pH 7.5, LAH4's antibacterial actions are two orders of magnitude more prominent[4].

References

[1]. Mason AJ, et al. The antibiotic and DNA-transfecting peptide LAH4 selectively associates with, and disorders, anionic lipids in mixed membranes. FASEB J. 2006;20(2):320-322. [2]. Langlet-Bertin B, et al. Design and evaluation of histidine-rich amphipathic peptides for siRNA delivery. Pharm Res. 2010;27(7):1426-1436. [3]. Zhang TT, et al. LAH4 enhances CD8+ T cell immunity of protein/peptide-based vaccines. Vaccine. 2012;30(4):784-793. [4]. Vogt TC, et al. The interactions of histidine-containing amphipathic helical peptide antibiotics with lipid bilayers. The effects of charges and pH. J Biol Chem. 1999;274(41):29115-29121.

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	0.3598 mL	1.7989 mL	3.5977 mL
	5 mM	0.0720 mL	0.3598 mL	0.7195 mL
	10 mM	0.0360 mL	0.1799 mL	0.3598 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.