LL-37

Name: LL-37
Brand: KAM Research
Availability: InStock

From $34.00to $645.00

For laboratory research use only. Not for human or animal use, consumption, diagnosis, treatment, or disease prevention.

This item is available only through approved account access.

Product Specifications

Lot Number: —
Purity: —
Storage Temp: 36°F to 46°F

For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.

Documentation

Certificates of Analysis are supplied with each product lot where applicable.

Certificate of Analysis (COA)

Documentation will be available once product lots are received and tested.

All products currently listed on this site are for research purposes only.

COA Library

Published Certificates of Analysis for LL-37. New deliveries are added as their batches are released.

No released COA for this strength yet

Reports appear here once a batch for this strength has been released.

Research Data

Chemical & Structural Identifiers

Chemical Name (IUPAC): 37-amino-acid human cathelicidin antimicrobial peptide corresponding to the C-terminal domain (residues 134–170) of human cationic antimicrobial protein (hCAP-18).
CAS Registry Number: 154947-66-7 (also cataloged in chemical indices under 597562-32-8)
PubChem CID: 16198951
Molecular Formula: C₂₀₅H₃₄₀N₆₀O₅₃
Molecular Weight: 4490.58 Da (4493.33 g/mol average)
Sequence: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
InChIKey: POIUWJQBRNEFGX-XAMSXPGMSA-N
Salt / Counter-Ion: Supplied as a lyophilized trifluoroacetate (CF₃COO^-) or acetate (CH₃COO^-) salt.
Synonyms: LL-37, Cathelicidin LL-37, hCAP-18 (134-170), Human Antimicrobial Peptide LL-37, CAMP(134-170), Ropocamptide.

Net Charge & Secondary Structure: Highly cationic (+6 net charge at neutral pH) forming an amphipathic α-helical conformation in membrane-mimetic environments.

Analytical & COA Specifications

Analytical Purity (RP-HPLC): ≥ 98.0% area normalization under UV detection at λ = 214 nm and 220 nm.
Identity Confirmation (ESI-MS / MALDI-TOF): Theoretical mass [M+H]⁺ = 4494.3 Da; observed mass matches expected multivalent charge envelopes ([M+4H]⁴⁺, [M+5H]⁵⁺, [M+6H]⁶⁺) within ± 1.0 Da.
Residual Moisture (Karl Fischer Titration): ≤ 3.0% water content.
Endotoxin Screening (LAL Assay): < 1.0 EU/mg (Limulus Amebocyte Lysate per USP <85>).
Sterility Validation: USP <71> compliant (no observed microbial proliferation in liquid media).
Physical Characterization: Dense, white to off-white lyophilized solid cake/powder.

Handling & Stability

Storage. Store dry solid desiccated at -20^°C to -80^°C, protected from atmospheric moisture and direct light.

Solubility. Freely soluble in sterile laboratory-grade deionized water (≥ 10 mg/mL), sterile Phosphate-Buffered Saline (PBS, pH 7.4), or dilute sterile 0.1% acetic acid for stock stabilization in in vitro assay applications.

Self-Assembly & Aggregation Kinetics: Exhibits concentration-dependent oligomerization and secondary structural transitions from unstructured random coil to an amphipathic α-helix in the presence of physiological anions (e.g., HCO₃^-, SO₄^2-); avoid high-shear vortexing and store single-use aliquots at -20^°C to eliminate degradation from repeated freeze-thaw cycles.

Mechanism & Literature

Biochemical Classification & Origin: The sole endogenous human cathelicidin antimicrobial peptide (CAMP), generated by the proteolytic cleavage of precursor protein hCAP-18 by neutrophil proteinase 3 or kallikrein endopeptidases during leukocyte degranulation.

Cellular Pathways Investigated: Evaluated across in vitro microbial models and cell culture systems:

References (3)

Gudmundsson, G. H., et al. (1996). The human gene FALL39 and processing of the cathelin-like protein to a 37-amino acid peptide LL-37 in granulocytes. European Journal of Biochemistry, 238(2), 325–332.
De Yang, et al. (2000). LL-37, the neutrophil granule- and epithelial cell-derived cathelicidin, utilizes formyl peptide receptor-like 1 (FPRL1) as a receptor in vitro. Journal of Experimental Medicine, 192(7), 1069–1074.
Overhage, J., et al. (2008). Human host defense peptide LL-37 prevents bacterial biofilm formation in vitro. Infection and Immunity, 76(9), 4176–4182.

Technical Laboratory FAQs

What structural characteristics govern LL-37 membrane interactions in vitro?

LL-37 possesses an amphipathic α-helical structure with a net positive charge of +6 at physiological pH, allowing its positively charged face to electrostatically bind anionic bacterial membranes while inserting its hydrophobic face into the lipid core to induce toroidal pore lysis.

Which mammalian cell surface receptors are engaged by LL-37 in signal transduction assays?

LL-37 functions as an agonist at Formyl Peptide Receptor 2 (FPR2 / FPRL1) and the ionotropic P2X₇ purinergic receptor, and stimulates the indirect shedding of EGFR ligands to activate intracellular MAPK/ERK cascades in cell culture modeling.

What solvent matrix is recommended for preparing in vitro LL-37 working stocks?

Sterile deionized water or sterile PBS (pH 7.4) dissolves the lyophilized powder rapidly at concentrations ≥ 10 mg/mL. For long-term stock stabilization against non-specific plastic adhesion in low-concentration biological assays, a carrier vehicle containing 0.1% laboratory-grade bovine serum albumin (BSA) or dilute 0.1% acetic acid is standard.

For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.