LL-37 5mg
LL-37 5mg · Result: 99.379% · Measured content: 4.74 mg (94.8% of label) · Report Code: D84HFXBSQWJ7 · Test Date: 2026-09-18 · Lab: Janoshik Analytical
View independent report #233646 ↗LL-37 5mg
♢ Research use only Class-level spec; selected lots Janoshik-tested
✓ Janoshik Verified 99.379%LL-37 5mg · Report #233646 ↗€76.99
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Full shipping informationLL-37 is a 37-amino acid peptide belonging to the cathelicidin family. It is the only human cathelicidin and has been widely studied for its role in innate immune signaling and host defense peptide research.
- Human cathelicidin host defense peptide
- Innate immune signaling and membrane interaction studies
- Biofilm disruption and microbiology research
For research purposes only. Not for human consumption.
Description
LL-37 is the only human cathelicidin — a class of host defense peptides that bridge innate immunity and antimicrobial defense. It is derived from the C-terminus of the hCAP-18 protein (human cathelicidin antimicrobial protein 18), processed by serine proteases into the active 37-amino acid LL-37 form. The name reflects its structure: it begins with two leucine residues (LL) and is 37 amino acids long. Despite being the sole human cathelicidin, it is expressed in neutrophils, epithelial cells of the skin, gut, lung, and urogenital tract — providing frontline defense at multiple barrier sites.
LL-37’s antimicrobial mechanism involves disruption of bacterial membranes. Its amphipathic alpha-helical structure allows it to insert into and permeabilize bacterial lipid bilayers, killing a broad spectrum of gram-positive and gram-negative bacteria, fungi, and enveloped viruses. It also binds and neutralizes bacterial LPS (endotoxin), a mechanism studied in models of endotoxin signalling. Beyond direct killing, LL-37 has extensive immunomodulatory functions — it activates epithelial cells, macrophages, and dendritic cells, modulates TLR signaling, and is studied for fibroblast and angiogenesis responses in tissue-repair model systems.
Research interest spans antimicrobial-peptide biology, tissue-repair model systems, skin-barrier-model and lung host-defense research, anti-biofilm strategies, and oncology research (LL-37 has context-dependent pro- and anti-tumor effects in different cancer models).
Specifications
| Parameter | Value |
|---|---|
| Compound | LL-37 (human cathelicidin antimicrobial peptide, 37 aa) |
| Amount per Vial | 5mg |
| Purity | ≥98% (class-level specification); selected lots independently tested by Janoshik, searchable by batch or report code at certapeptides.com/verify |
| Format | Lyophilized powder |
| Reconstitution | Sterile water; avoid high salt concentrations |
| Storage | -20°C; 2-8°C after reconstitution |
Storage
Store at -20°C. LL-37 can aggregate in high ionic strength solutions — reconstitute in low-salt buffer or sterile water and then add buffer. Refrigerate at 2-8°C after reconstitution and use within 14 days. Avoid repeated freeze-thaw.
How does LL-37 kill bacteria without killing host cells?
LL-37 kills bacteria by disrupting their membranes through its amphipathic alpha-helical structure — one face of the helix is hydrophobic, the other cationic. Bacterial membranes are negatively charged due to high phosphatidylglycerol and cardiolipin content, attracting the cationic LL-37. Once bound, the peptide inserts into and permeabilizes the bacterial membrane. Mammalian cell membranes are primarily zwitterionic (net neutral) and are less susceptible to this mechanism, though selectivity is concentration-dependent. High LL-37 concentrations can lyse mammalian cells. Research protocols must account for this concentration-dependent selectivity.
Why is LL-37 the only human cathelicidin?
While mice and many other mammals have multiple cathelicidin genes, humans have only one — the CAMP gene encoding the hCAP-18/LL-37 precursor. The reasons for this reduction to a single cathelicidin in human evolution are not fully understood, but it may relate to immune system specialization in humans toward other defense mechanisms. Despite being alone in its class, LL-37 is expressed at many epithelial surfaces and in immune cells, and its immunomodulatory functions extend well beyond direct antimicrobial killing — suggesting it has evolved to serve multiple host defense roles that might be distributed across multiple cathelicidins in other species.
What is LL-37’s role in tissue-repair model research?
LL-37 is studied for tissue-repair responses in model systems through several mechanisms. In cited models it is associated with keratinocyte migration and proliferation, angiogenesis signalling through VEGF and FGF receptor pathways, and modulation of the inflammatory phase of tissue-repair models, alongside anti-biofilm activity studied in antimicrobial-model systems. These properties have made LL-37 of interest in barrier-model and anti-biofilm research. LL-37-functionalised dressings and scaffolds have also been investigated in tissue-repair model systems.
LL-37 is supplied for research purposes only. Not for human use. Handle in compliance with institutional biosafety guidelines.
| Parameter | Value |
|---|---|
| Compound | LL-37 (human cathelicidin antimicrobial peptide, 37 aa) |
| Amount per Vial | 5mg |
| Purity | ≥98% (class-level specification); selected lots independently tested by Janoshik, searchable by batch or report code at certapeptides.com/verify |
| Format | Lyophilized powder |
| Reconstitution | Sterile water; avoid high salt concentrations |
| Storage | -20°C; 2-8°C after reconstitution |
Store at -20°C. LL-37 can aggregate in high ionic strength solutions — reconstitute in low-salt buffer or sterile water and then add buffer. Refrigerate at 2-8°C after reconstitution and use within 14 days. Avoid repeated freeze-thaw.
What research shows
Selected peer-reviewed studies from the published literature. Each describes laboratory or preclinical findings and is attributed to the cited study, not to this product. For research purposes only — not medical guidance.
[1]
Immunomodulation
In cultured macrophages, LL-37 was shown to inhibit LPS/ATP-induced pyroptosis through a dual mechanism in in-vitro research.
Antimicrobial cathelicidin peptide LL-37 inhibits the LPS/ATP-induced pyroptosis of macrophages by dual mechanism. PLoS One (2014). PMID: 24454930Citations are provided for research reference. CertaPeptides (CERTALAB S.R.L.) is a reseller, not a manufacturer, and makes no medical, therapeutic, or efficacy claims. Products are for research purposes only and are not for human or animal consumption.
Researcher Confidence
Why researchers choose CertaPeptides
Who actually tests this?
Selected lots are independently verified by Janoshik Analytical (Czech Republic) and published on the Janoshik public portal. Other lots ship with the supplier's batch specification. See /coa for the published wall.
View COAs →What if I get the wrong batch?
Every vial label carries a code. Look it up on our Verify page: it shows what CertaPeptides publishes for that code and, for a withdrawn lot, that the lot was withdrawn and why. If yours is withdrawn, or if the code on your label finds nothing, email us that code.
View COAs →Where does it ship from?
Romania (EU). We are CERTALAB SRL, CUI 54169956, VAT-registered. Sameday for Romania, GLS for most EU destinations, TCE Worldwide for the remaining cross-border EU and non-EU markets (UK, Switzerland). Delivery 1–15 business days depending on destination — exact window shown at checkout.
Shipping details →What if there's a problem?
You have a 14-day withdrawal right under OUG 34/2014 (Romanian/EU consumer law), with escalation to ANPC and alternative dispute resolution (SAL) available. Contact us at support@chinapeptideshop.com.
Returns policy →Product Information
This product is intended for scientific research and development purposes only. It is a chemical substance that shall not be used as a drug, medicine, active substance, or ingredient in any product intended for human or animal consumption. Researchers must handle this compound in accordance with their institutional biosafety guidelines. Use only in properly equipped laboratory settings with appropriate personal protective equipment.
Peptides in lyophilized (freeze-dried) form are shipped in sealed glass vials using standard delivery methods and do not require refrigeration during transit. Lyophilized peptides are highly stable at ambient temperatures for the duration of standard shipping (typical transit windows are shown at checkout). Once received, transfer the product to refrigerated storage (2–8°C) promptly.
Frequently Asked
Research peptides are supplied in lyophilized (freeze-dried) form. The amount of material is typically only a few milligrams — appearing as a very thin film or small pellet at the bottom of the vial, often nearly invisible. This is completely normal.
Unlike some suppliers who add bulk fillers (such as Mannitol), CertaPeptides provides pure peptide without unnecessary additives.
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