Description
LL-37 is the only cathelicidin antimicrobial peptide made by humans: a 37-residue host-defence peptide that kills microbes, signals to immune cells and is switched on by vitamin D. It is a standard reference peptide in microbiology and innate-immunity research. Pure Peptides Canada supplies it as a lyophilized research reagent in 5 mg vials, with an independent Janoshik HPLC and mass-spectrometry report, CAD pricing and tracked shipping from inside Canada.
LL-37 at a glance
- What it is: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES, a cationic, amphipathic peptide cut from the C-terminus of the protein hCAP18.
- What researchers study: membrane disruption of bacteria and biofilms, immune-cell signalling, wound re-epithelialization, and its role in skin conditions such as psoriasis.
- Evidence level: extensive cell and animal work, plus small early-phase human studies of topical formulations.
- Supplied as: sealed lyophilized powder, 5 mg, single vial or box of 10.
- Delivery: ships from inside Canada by tracked Xpresspost in 3–7 days ($25 CAD), or free in 4–12 days on orders over $299.
LL-37
Human cathelicidin · hCAP18(134-170) · CAMP gene product
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The name comes from its first two residues (Leu-Leu) and its length (37).
- Length
- 37 amino acids
- Molecular formula
- C205H340N60O53
- Molecular weight
- ≈ 4493 g/mol
- CAS number
- 154947-66-7
- Net charge
- Strongly cationic (+6 at neutral pH)
- Form
- Lyophilized powder, sealed vial
- Sizes
- 5 mg (single or box of 10)
- SKU
- PP-LL37
Where the evidence stands
- Cell studies
- Animal models
- Small human studies
- Approved medicine
Human data is limited to small early-phase studies of topical LL-37. It is not an approved medicine.
What is LL-37?
Cathelicidins are host-defence peptides found across mammals, but humans make only one. Its precursor, hCAP18, is stored in neutrophils and produced by skin and mucosal cells, and cleaving off the C-terminal 37 residues releases LL-37. Its positive charge and amphipathic shape let it insert into and disrupt bacterial membranes, and it also binds and neutralizes bacterial endotoxin.
LL-37 turned out to be much more than an antibiotic. It recruits and signals to immune cells, promotes skin-cell migration and new blood vessels in wound models, and is strongly induced by vitamin D through the CAMP gene. It also has a darker side in research: complexes of LL-37 with self-DNA activate plasmacytoid dendritic cells and are implicated in psoriasis, and excess LL-37 is studied in rosacea. That dual role makes it a rich tool for innate-immunity research.
What LL-37 research looks at
- Antimicrobial activity: bacterial membrane disruption, biofilm inhibition and endotoxin neutralization.
- Immune signalling: chemotaxis and receptor interactions including FPR2 and P2X7.
- Wound models: keratinocyte migration and angiogenesis.
- Vitamin D biology: VDR-driven induction of the CAMP gene.
- Autoimmune skin models: LL-37–DNA complexes and TLR9 activation in psoriasis research.
Handling note: LL-37 is cationic and amphipathic, so it can stick to plastics and aggregate in some buffers. Low-binding tubes and deliberate buffer choice help. Regulatory status: LL-37 is not an authorized drug in Canada. We sell it strictly as a laboratory reagent for in-vitro research.
Why researchers order LL-37 from Pure Peptides Canada
Add a 5 mg vial or a box of 10 above. Orders over $299 ship free across Canada.
See lab resultsChecking an LL-37 identity report
These are the figures to look for when you open the mass-spectrometry result for an LL-37 peptide batch. They are calculated from the 37-residue sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES (C205H340N60O53):
- Electrospray charge states: with 6 lysines and 5 arginines, LL-37 picks up several protons, so electrospray shows a ladder of multiply charged ions rather than one main peak: [M+4H]4+ m/z 1124.3, [M+5H]5+ m/z 899.7, [M+6H]6+ m/z 749.9 and [M+7H]7+ m/z 642.9 (average m/z).
- Deconvoluted mass: when software combines that ladder into one neutral mass, the result should be near 4493.3 Da (average), or 4490.58 Da monoisotopic on a high-resolution instrument.
- MALDI: if the report uses MALDI instead, look for the singly charged ion, [M+H]+, at about m/z 4494.3 (average).
Our guide to reading peptide mass spectra walks through charge-state ladders and deconvolution in more detail, and the Lab Testing page collects our independent Janoshik reports by product and batch.
LL-37 FAQ
Where can I buy LL-37 in Canada?
Pure Peptides Canada stocks LL-37 as a lyophilized research reagent in 5 mg vials and ships it from inside Canada by tracked Xpresspost in 3–7 days ($25 CAD), or free in 4–12 days on orders over $299.
Why is it called LL-37?
It starts with two leucine residues (LL) and is 37 amino acids long.
How is LL-37 related to vitamin D?
The gene that encodes its precursor, CAMP, carries a vitamin D response element. Active vitamin D strongly induces LL-37 production in immune and epithelial cells, which is a major research topic. Our LL-37 guide covers it in detail.
Is this LL-37 third-party tested?
Yes. The listing links an HPLC purity and mass-spectrometry identity report from Janoshik Analytical, an independent lab. Our COA guide explains how to read it.
Can LL-37 be used in people or animals?
No. This product is for in-vitro laboratory research only and is not a drug, supplement, cosmetic or food. We do not provide dosing or administration information.
For laboratory research use only. Not a drug, supplement, food or cosmetic, not for human or veterinary use, and not intended to diagnose, treat, cure or prevent any disease.
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