To buy LL-37 peptide in the USA for laboratory research, institutional investigators require verified purity, lot-specific analytical documentation, and reliable domestic sourcing. PX1 Research supplies analytical-grade, US-manufactured LL-37 peptide complete with third-party HPLC and Mass Spectrometry validation for preclinical, cellular, and microbiological research applications.
To buy LL-37 peptide in the USA for laboratory research, institutional investigators require verified purity, lot-specific analytical documentation, and reliable domestic sourcing. PX1 Research supplies analytical-grade, US-manufactured LL-37 peptide complete with third-party HPLC and Mass Spectrometry validation for preclinical, cellular, and microbiological research applications.
Laboratories seeking to buy LL-37 peptide in the USA for preclinical investigation must prioritize chemical integrity, lot-to-lot consistency, and rapid domestic logistics. As a primary endogenous human cathelicidin derivative, LL-37 is extensively evaluated in assays examining innate immune activation, antimicrobial membrane perturbation, and cellular migration dynamics. When procuring reagents for quantitative assays, purchasing unverified material can introduce experimental confounding factors such as residual trifluoroacetic acid (TFA) salts, synthesis artifacts, or bacterial endotoxin contamination.
PX1 Research fulfills the rigorous requirements of academic, clinical, and biotechnology research facilities across the United States. All batches of our LL-37 peptide undergo exhaustive analytical testing, including Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) for purity assessment and Electrospray Ionization Mass Spectrometry (ESI-MS) for sequence confirmation. Shipped directly from state-of-the-art logistics centers in California and Arizona, PX1 Research provides researchers with reliable access to high-purity host-defense compounds supported by comprehensive documentation.
LL-37 is a 37-amino-acid cationic peptide derived from the C-terminus of the human cathelicidin precursor protein hCAP18 (human Cationic Antimicrobial Protein 18 kDa). Represented by the primary sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES, LL-37 possesses a net positive charge of +6 at physiological pH due to an abundance of lysine and arginine residues. In aqueous environments, the peptide adopts a predominantly random-coil conformation, but transitions into an amphipathic alpha-helix upon interacting with hydrophobic interfaces or phospholipid membranes.
The amphipathic design separates hydrophilic, positively charged residues along one face of the helix from hydrophobic residues on the opposing face. This structural duality is fundamental to the physical chemistry of cathelicidins. Researchers investigating structural biology utilize synthesized LL-37 to analyze lipid-membrane partitioning, secondary structure transitions via circular dichroism, and self-assembly dynamics under varying ionic strength and pH conditions. Understanding these biophysical properties is critical when designing reproducible in vitro models.
In vitro models demonstrate that LL-37 exhibits pronounced affinity for negatively charged phospholipid bilayers, such as those rich in phosphatidylglycerol and cardiolipin typically found in bacterial cell membranes. Preclinical research suggests that the cationic domain of LL-37 initiates electrostatic binding with anionic lipid headgroups, allowing the hydrophobic face to insert into the fatty acyl core. This process destabilizes membrane integrity through mechanisms commonly described as the carpet model, toroidal pore formation, or detergent-like micellization.
Beyond direct membrane disruption, researchers utilize LL-37 in biofilm research models to evaluate its capacity to inhibit bacterial aggregation and disrupt established extracellular polymeric substances (EPS). In vitro studies indicate that sub-inhibitory concentrations of LL-37 can downregulate genes responsible for flagellar motility and quorum sensing in specific bacterial strains. Investigating these non-lytic mechanisms provides valuable insight into how host-defense peptides modulate microbial architecture without selecting for traditional drug-resistance pathways.
While recognized for membrane-active properties, LL-37 acts as a multifunctional immunomodulatory ligand in preclinical cell-culture assays. Research indicates that LL-37 interacts with several cell-surface receptors, prominently including Formyl Peptide Receptor 2 (FPR2/ALX), P2X7 purinergic receptors, and Toll-like receptors (TLRs). Through FPR2 binding, LL-37 initiates intracellular signaling cascades that mediate chemotaxis in neutrophils, monocytes, and T-lymphocytes within experimental models.
Additionally, LL-37 exhibits high-affinity binding to lipopolysaccharide (LPS), a major outer-membrane component of Gram-negative bacteria. In vitro assays demonstrate that by sequestering free LPS, LL-37 can prevent LPS from engaging the TLR4/MD-2 complex, thereby attenuating pro-inflammatory NF-kB activation and downstream cytokine secretion (e.g., TNF-alpha, IL-6). Researchers exploring sepsis models and inflammatory control frequently utilize LL-37 to investigate the balance between neutralizing bacterial endotoxins and recruiting immune effector cells.
In cell culture and organoid research models, LL-37 has been shown to influence key cellular processes involved in tissue regeneration and matrix remodeling. Preclinical studies suggest that LL-37 stimulates keratinocyte and endothelial cell proliferation and migration via epidermal growth factor receptor (EGFR) transactivation. In vitro scratch-assay models consistently document accelerated cellular re-epithelialization upon exposure to controlled concentrations of synthesized cathelicidin peptides.
Furthermore, researchers explore LL-37 in vascularization assays. In vitro tubulogenesis models suggest that LL-37 promotes capillary-like tube formation in human umbilical vein endothelial cells (HUVECs). By regulating vascular endothelial growth factor (VEGF) pathway components and modulating matrix metalloproteinase (MMP) expression, LL-37 serves as a benchmark compound for studying the interplay between innate host defense and tissue restructuring.
To select the appropriate research tool for host-defense, anti-inflammatory, or cellular migration studies, investigators frequently compare LL-37 against other signaling peptides. While LL-37 offers dual antimicrobial and immunomodulatory activity, compounds like KPV—a tripeptide derivative of alpha-MSH—are studied primarily for their focused suppression of NF-kB-mediated inflammatory signaling without direct membrane-lytic action. Researchers interested in broader signaling models can explore our catalog of research peptides to compare structural properties across different compound classes.
Similarly, in tissue restoration models, investigators often contrast LL-37 with synthetic signaling peptides such as BPC-157 or Thymosin Beta-4. While BPC-157 and Thymosin Beta-4 operate principally through nitric oxide pathways, actin sequestration, and growth factor upregulation, LL-37 uniquely combines amphipathic bacterial membrane disruption with chemokine receptor modulation. Reviewing specialized topics in our peptide research library provides further context on selecting the correct control or primary compound for comparative study designs.
To maintain the structural integrity of LL-37 peptide during laboratory storage and reconstitution, research teams must adhere to standardized biochemical protocols. Lyophilized LL-37 should be stored at -20°C or -80°C upon arrival, protected from light and moisture. Prior to opening the vial, allow the container to equilibrate to room temperature to prevent condensation from introducing moisture to the cake, which can accelerate hydrolytic degradation.
Reconstitution should be performed using sterile, deionized water or low-salt buffers such as dilute acetic acid (10–100 mM) to ensure complete dissolution, as high-ionic-strength phosphate-buffered saline (PBS) may induce self-aggregation or precipitation at high peptide concentrations. Once reconstituted, stock solutions should be aliquoted into polypropylene microcentrifuge tubes to avoid repeated freeze-thaw cycles and minimize peptide adsorption to glass surfaces. Detailed reconstitution metrics can be found in our technical guide on cathelicidin signaling mechanisms.
When procurement officers decide to buy LL-37 peptide in the USA, verifying supplier quality standards is paramount to ensuring experimental reproducibility. Substandard peptides containing truncated synthesis fragments or counter-ion impurities can alter cellular responses, yielding false-positive or irreproducible data. High-quality LL-37 must be validated by RP-HPLC to confirm chemical purity equal to or exceeding 98.0%, and ESI-MS to confirm the exact molecular weight of 4493.3 Da.
Furthermore, because LL-37 is frequently employed in LPS-neutralization and immunological assays, strict endotoxin control is essential. PX1 Research conducts chromogenic Limulus Amebocyte Lysate (LAL) testing on every production lot, verifying that endotoxin levels remain strictly controlled (typically <0.05 EU/mg). Manufactured in cGMP-compliant facilities and tested by ISO 17025 accredited analytical laboratories, PX1 Research provides fully traceable batch documentation with every order.
PX1 Research simplifies domestic procurement for academic institutions, government laboratories, and private research enterprises across the United States. Orders are processed with same-day dispatch from our California and Arizona fulfillment hubs for Monday through Friday requests placed before cut-off times. This dual-coast shipping architecture minimizes transit times and preserves cold-chain integrity during transport.
Principal investigators and procurement departments requiring bulk quantities or recurring delivery schedules can access streamlined ordering through PX1 Research wholesale accounts. Every shipment includes lot-specific Certificates of Analysis (COAs) containing raw HPLC chromatograms and mass spectra. Explore our full spectrum of host-defense tools within our specialized antimicrobial research peptides section to support your laboratory's ongoing experimental protocols.
Where can institutional investigators buy LL-37 peptide in the USA for laboratory research?
Institutional investigators can buy LL-37 peptide in the USA directly through PX1 Research. All products are manufactured in US facilities, tested by ISO 17025 accredited laboratories, and shipped same-day from California and Arizona hubs with full HPLC and Mass Spectrometry validation.
What primary analytical metrics verify LL-37 purity and identity?
Purity and identity are verified using Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) to confirm purity (typically >=98%), Electrospray Ionization Mass Spectrometry (ESI-MS) to verify the target mass of 4493.3 Da, and LAL testing to measure residual endotoxin levels.
What is the molecular weight and sequence of human LL-37 peptide?
LL-37 is a 37-amino-acid peptide with the sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES. It has a calculated molecular weight of approximately 4493.3 g/mol (Da) and a net positive charge of +6 at neutral pH.
How should lyophilized LL-37 peptide be stored upon delivery?
Lyophilized LL-37 should be stored desiccated at -20°C or -80°C upon receipt. Vials should be allowed to reach room temperature before opening to prevent atmospheric moisture condensation.
What diluents are recommended for reconstituting LL-37 in research assays?
Reconstitution is recommended using sterile, endotoxin-free water or 10–100 mM dilute acetic acid to prevent peptide self-aggregation. Avoid initial dissolution in high-salt PBS, which can cause precipitation at elevated concentrations.
Why is endotoxin testing critical for LL-37 research compounds?
Because LL-37 is frequently studied for its LPS-binding and immune-modulating properties, baseline endotoxin contamination in the peptide reagent would confound cell-culture results and TLR activation assays. PX1 Research tests every lot to ensure low endotoxin levels.
How does LL-37 compare to other host-defense peptides like KPV?
LL-37 is a 37-residue amphipathic alpha-helical cathelicidin that combines direct microbial membrane disruption with FPR2 signaling. KPV is a tripeptide derived from alpha-MSH focused primarily on intracellular anti-inflammatory signaling pathways without membrane-lytic activity.
Does PX1 Research provide bulk ordering options for university laboratories?
Yes, PX1 Research provides institutional accounts, custom batch synthesis, and bulk procurement options for university, government, and corporate biotechnology research facilities across the USA.
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.