- ≥99% by HPLC; lot-matched COA available
- Lot-matched certificate of analysis
- Ships next business day, tracked
LL-37 (Cathelicidin)
Human cathelicidin LL-37, a 37-residue antimicrobial host-defence peptide
- FormLyophilized powder, sealed glass vial with crimped stopper
- Mol. weight4493.33 g/mol
- Research areasAntimicrobial and antibiofilm assays, wound repair, immunomodulation, barrier immunity
Supplied for laboratory research use only. Not for human or veterinary use, and not intended to diagnose, treat, cure or prevent any disease.
Overview
LL-37 is the only cathelicidin-family antimicrobial peptide found in humans. It is released from the C-terminus of the precursor protein hCAP18 by proteinase 3 cleavage and takes its name from its length and its two leading leucine residues. Neutrophils, epithelial cells and keratinocytes all express it, and it sits at the interface between innate antimicrobial defence and the regulation of inflammation.
Structurally it is a cationic, amphipathic alpha helix of thirty-seven residues carrying a strong net positive charge. That geometry is central to the mechanism most often described in the literature: electrostatic association with anionic bacterial membranes followed by disruption of membrane integrity. The same amphipathic character makes it a demanding peptide to synthesise and purify, which is reflected in its price relative to shorter sequences.
Supplied as a lyophilized powder in sealed 5 mg and 10 mg vials, each lot is purified by reversed-phase HPLC to at least 99% with mass confirmation and a lot-matched certificate of analysis. Laboratories study it in antimicrobial assays, biofilm work, wound models and immunomodulation research. It is sold strictly for laboratory research use.
Specifications
Identity
- CAS number
- 154947-66-7
- Molecular weight
- 4493.33 g/mol
- Amino acid sequence
- LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
- Chain length
- 37 amino acids
- Peptide class
- Cathelicidin-family antimicrobial host-defence peptide
Supply & purity
- Form
- Lyophilized powder, sealed glass vial with crimped stopper
- Purity
- ≥99% by HPLC; lot-matched COA available
- Available sizes
- 5 mg, 10 mg
Handling & storage
- Storage (lyophilized)
- −20 °C, sealed and protected from light and moisture
- Storage (reconstituted)
- 2–8 °C, protected from light, used within the study window
Additional detail
- Precursor
- hCAP18; released by proteinase 3 cleavage of the C-terminal domain
- Structure
- Cationic amphipathic alpha helix with a strong net positive charge
- Research areas
- Antimicrobial and antibiofilm assays, wound repair, immunomodulation, barrier immunity
Questions about LL-37 (Cathelicidin)
What is LL-37?
LL-37 is the only cathelicidin antimicrobial peptide expressed in humans, a thirty-seven residue cationic helix released from the hCAP18 precursor protein. It is supplied here as a lyophilized research powder for antimicrobial, biofilm, wound-repair and immunomodulation studies.
Why is LL-37 more expensive than shorter peptides?
At thirty-seven residues it is long by synthesis standards, and its amphipathic, highly cationic character makes both the coupling steps and the purification harder than for a short hydrophilic sequence. Yield per synthesis run is lower, and that cost is reflected in the price per milligram.
What purity do you supply and is a COA available?
Every lot is purified and analysed by reversed-phase HPLC to at least 99% with mass-spectrometric confirmation against the expected 4493.33 g/mol mass. A certificate of analysis matched to the lot number on your vial is available on request before or after ordering.
Does LL-37 need special handling?
It benefits from it. The peptide adsorbs to plastic and aggregates more readily than short hydrophilic sequences, so laboratories generally use low-binding tubes, avoid vortexing and prepare working dilutions fresh rather than storing very dilute stocks for long periods.
What research areas does LL-37 appear in?
Membrane-directed antimicrobial assays against bacteria, fungi and enveloped viruses; biofilm interference at sub-lethal concentrations; wound-repair models involving keratinocyte migration; and immunomodulation work covering lipopolysaccharide binding and dendritic cell responses, including its implicated role in psoriasis.
Can LL-37 be used outside a laboratory?
No. This vial is a research chemical supplied for in-vitro and laboratory investigation by qualified personnel. It is not a drug, supplement or medical product, has no approval for human or veterinary administration, and ships without any dosing or protocol guidance.
Related
