When selecting an LL-37 vendor, laboratory investigators require verified chemical purity, precise lot-to-lot consistency, and comprehensive analytical documentation. PX1 Research supplies USA-manufactured LL-37 synthesized under strict quality controls, verified via reverse-phase HPLC and mass spectrometry, and tested for low endotoxin levels to ensure reproducible results in preclinical research.
When selecting an LL-37 vendor, laboratory investigators require verified chemical purity, precise lot-to-lot consistency, and comprehensive analytical documentation. PX1 Research supplies USA-manufactured LL-37 synthesized under strict quality controls, verified via reverse-phase HPLC and mass spectrometry, and tested for low endotoxin levels to ensure reproducible results in preclinical research.
Sourcing peptides for cellular and biophysical assays demands rigorous supplier auditing. Because host defense peptides like LL-37 interact directly with cell membranes and immune receptors, even minor impurities or residual synthesis byproducts can significantly alter experimental outcomes. Principal investigators and laboratory managers must evaluate an LL-37 vendor based on analytical transparency, manufacturing standards, and batch consistency.
A trustworthy vendor must provide lot-specific documentation verifying both identity and purity. Essential analytical metrics include Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) chromatograms demonstrating ≥98% purity, Electrospray Ionization Mass Spectrometry (ESI-MS) confirming exact molecular weight, and quantitative endotoxin testing. PX1 Research manufactures research compounds in USA-based, GMP-compliant facilities and verifies every lot through independent ISO 17025 accredited testing laboratories.
LL-37 is the sole amphipathic alpha-helical peptide belonging to the cathelicidin family identified in humans. Cleaved proteolytically from the C-terminal domain of the human cationic antimicrobial protein 18 (hCAP18) by proteinase 3, LL-37 consists of 37 amino acid residues beginning with two leucine residues (LL37: Leu-Leu-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gln-Gly-Ser-Phe-Lys-Asp-Leu-Val-Gln-Arg-Ala-Lys-Asp-Leu-Val-Gln-Arg-Ala-Lys-Asp-Leu-Val-Gln-Arg-Ala...).
In physiological and experimental settings, LL-37 exhibits an overall net positive charge (+6 at neutral pH) due to its abundance of basic lysine and arginine residues. This cationic nature, paired with a distinct hydrophobic face, allows the peptide to adopt a secondary amphipathic alpha-helical structure upon interaction with phospholipid membranes. To explore our broader catalog of host defense agents, scientists can browse our complete line of research peptides.
In vitro models demonstrate that LL-37 primary antimicrobial activity occurs through non-specific biophysical membrane permeabilization rather than receptor-mediated enzyme inhibition. The cationic region of the peptide binds electrostatically to negatively charged bacterial lipopolysaccharides (LPS) in Gram-negative strains or teichoic acids in Gram-positive strains.
Upon initial electrostatic association, the hydrophobic domain inserts into the lipid bilayer. Structural studies indicate that LL-37 operates via carpet-like or toroidal pore mechanisms, disrupting membrane integrity, inducing transmembrane potential collapse, and causing cytosolic leakage. Because these biophysical dynamics depend heavily on charge density, ordering from a validated supplier ensures that truncated sequences do not skew experimental observations.
Beyond direct membrane disruption, preclinical research focuses on how LL-37 modulates host immune pathways. In vitro assays reveal that LL-37 can act as a chemoattractant for neutrophils, monocytes, and T-cells by signaling through the Formyl Peptide Receptor-Like 1 (FPRL1/FPR2). This receptor interaction triggers intracellular calcium mobilization and activates downstream MAPK/ERK kinase pathways.
In addition, LL-37 is extensively studied in biofilm-environment models. Biofilms present a persistent physical barrier in chronic wound studies due to extracellular polymeric substances (EPS). In vitro studies indicate that sub-inhibitory concentrations of LL-37 interfere with bacterial quorum sensing, downregulate genes required for flagellar assembly, and inhibit initial bacterial attachment, preventing mature biofilm formation.
In tissue-culture and animal wound models, LL-37 exhibits multifaceted signaling behavior. Rodent models of re-epithelialization demonstrate that LL-37 stimulates vascular endothelial growth factor (VEGF) expression and accelerates keratinocyte migration. These actions are mediated via epidermal growth factor receptor (EGFR) transactivation.
Researchers evaluating tissue regeneration pathways often analyze LL-37 alongside other bioactive peptides. For detailed literature on peptide-driven cellular migration and tissue modeling, consult our research hub. Laboratories scaling up experimental models can also access bulk sourcing options through our dedicated wholesale program.
When designing comparative assays for tissue repair, cellular signaling, or host defense, investigators frequently benchmark LL-37 against other well-characterized signaling peptides. While LL-37 acts primarily as a cationic amphipathic host defense peptide modulating FPR2 and membrane stability, compounds like BPC-157 are studied for their effects on nitric oxide pathways, VEGFR2 expression, and focal adhesion kinase activity. Similarly, TB-500 (a fragment of Thymosin Beta-4) is utilized in cell-migration assays focusing on actin sequestration, and KPV is evaluated for its alpha-MSH derived anti-inflammatory signaling. Comparing these distinct mechanisms allows laboratories to isolate membrane-active responses from intracellular signaling cascades.
For host defense peptides, analytical verification goes beyond simple purity percentages. Residual trifluoroacetic acid (TFA) salts, organic solvents, or bacterial endotoxins (LPS) from expression or synthesis vectors can cause unspecific cellular toxicity or false-positive immune activation in cell culture.
PX1 Research ensures that every batch of LL-37 undergoes rigorous quality control. Our verification process includes:
• RP-HPLC Analysis: Confirms single-peak chromatograms with target purity typically exceeding 98%.
• Mass Spectrometry (ESI-MS): Verifies exact monoisotopic mass to rule out deletion sequences or oxidation.
• LAL Endotoxin Testing: Measures Limulus Amebocyte Lysate reactivity to guarantee endotoxin levels remain below strict threshold limits (<0.01 EU/μg).
• ISO 17025 Certified Testing: All COAs are issued by independent, accredited analytical testing laboratories.
Proper handling is critical to prevent peptide aggregation, adhesion to container walls, or premature degradation. LL-37 is supplied as a lyophilized powder under inert gas.
1. Storage of Lyophilized Powder: Store at -20°C or -80°C in a desiccated environment upon receipt. Avoid exposure to ambient moisture.
2. Reconstitution Strategy: Reconstitute using sterile, nuclease-free water or low-salt buffered solution (e.g., 10 mM phosphate buffer, pH 7.4). Due to the cationic nature of LL-37, hydrophobic binding to non-passivated glass or standard plastic tubes can occur; utilize low-binding polypropylene tubes.
3. Solubilization Avoidance: Avoid high ionic strength buffers during initial dissolution to prevent aggregation before complete solvation.
4. Aliquoting and Working Solutions: Once reconstituted, aliquot into single-use experimental volumes to avoid repeated freeze-thaw cycles. Store working aliquots at -80°C for long-term stability.
PX1 Research is dedicated to supplying the scientific community with premium, USA-manufactured research peptides. We eliminate sourcing ambiguity by maintaining complete transparency across production and distribution.
Orders are dispatched directly from our domestic facilities located in California and Arizona, offering same-day shipping for orders placed Monday through Friday before cut-off times. By providing accessible lot-specific COAs, verified purity profiles, and dedicated support for laboratory procurement, PX1 Research stands as the premier partner for academic, biotechnology, and institutional research.
What is the certified purity level of PX1 Research LL-37?
PX1 Research supplies LL-37 verified at ≥98% purity by Reverse-Phase HPLC. Each lot is accompanied by a third-party Certificate of Analysis (COA) confirming identity via mass spectrometry.
Where is PX1 Research LL-37 manufactured and shipped from?
Our LL-37 is manufactured in USA-based, GMP-compliant facilities. All orders ship directly from our domestic distribution centers in California and Arizona.
Why is endotoxin testing essential for LL-37 research compounds?
Because LL-37 is frequently used in innate immunity and inflammation assays, background endotoxins (LPS) can mask experimental data by prematurely activating Toll-like receptors (TLR4). PX1 Research conducts LAL endotoxin testing on every lot to guarantee minimal background reactivity.
What solvent is recommended for reconstituting LL-37 in vitro?
For in vitro assays, LL-37 is typically reconstituted in sterile, deionized, nuclease-free water or a dilute, non-denaturing buffer (such as 10 mM sodium phosphate, pH 7.4). The use of low-binding polypropylene labware is recommended to prevent peptide adsorption to tube walls.
How should reconstituted LL-37 solutions be stored?
Reconstituted solutions should be aliquoted into single-use volumes and stored at -80°C to prevent degradation and physical aggregation caused by repeated freeze-thaw cycles.
What molecular targets does LL-37 interact with in preclinical models?
In preclinical literature, LL-37 is documented to interact with bacterial cell membrane phospholipids, Formyl Peptide Receptor-Like 1 (FPRL1/FPR2), P2X7 purinergic receptors, and EGFR via transactivation pathways.
Can LL-37 be ordered in bulk for institutional research projects?
Yes. PX1 Research supports institutional procurement and large-scale studies through our wholesale research account framework. Bulk lots are supplied with matching lot verification and custom analytical testing upon request.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.