62304-98-7
Thymosin Alpha-1
28-residue N-acetylated thymic peptide studied in T-cell maturation and innate signalling.
Typical release98.8%
From
£72.00
In stock
Immune & Signalling
LL-37
Cathelicidin LL-37 · hCAP18(134-170)
37-residue cationic host defence peptide, the sole human cathelicidin.
Total, ex VAT
£98.00
- Released at ≥ 98.0% (RP-HPLC, area %)
- Identity confirmed by ESI-MS against theoretical mass
- Batch certificate matched to the vial, verifiable online
- Same working day dispatch before 14:00, tracked
For laboratory research use only. Not for human or veterinary use, and not a medicine, food or cosmetic. Sold to qualified researchers and institutions who accept responsibility for safe handling and lawful use.
Compound data
What is in the vial
Indicative values for this line. The certificate issued with your batch is the authoritative record and reports the measured figures for the material you receive.
- CAS number
- 154947-66-7
- Molecular formula
- C205H340N60O53
- Average mass
- 4493.3 g/mol
- Residues
- 37
- Class
- Cationic host defence peptide (cathelicidin)
- Form as supplied
- Lyophilised powder
- Appearance
- White to off-white lyophilised powder
- Purity specification
- ≥ 98.0% (RP-HPLC, area %)
- Solubility
- Soluble in water, but strongly adsorbs to glass and untreated plastic. Use low-binding consumables throughout.
- Storage
- Lyophilised: −20 °C, desiccated and dark. Reconstituted: 2–8 °C.
Targets and pathways
- Bacterial membranes
- Formyl peptide receptor 2 (FPR2)
- Innate immune signalling
Overview
About LL-37
LL-37 is the only cathelicidin in humans, released from the hCAP18 precursor by proteolytic cleavage. It is strongly cationic and amphipathic, forming an alpha helix on contact with a membrane — the structural basis of its antimicrobial activity.
That same cationic character is the practical problem in handling it. LL-37 adsorbs readily to glass and to untreated plastic, and at working concentrations losses to container surfaces can exceed the amount reaching the assay. Low-binding consumables throughout, and a carrier protein where the assay tolerates one, are the usual mitigations.
In short
- The only human cathelicidin, 37 residues, strongly cationic
- Adsorbs heavily to glass and untreated plastic — low-binding consumables required
- Both direct antimicrobial and immunomodulatory activity
- Released at ≥ 98.0% area-percent by RP-HPLC
Where it is used
Research applications
Membrane interaction
The amphipathic helix and its interaction with bacterial membranes is the founding line of research.
Immunomodulation
Signalling through FPR2 and effects on chemotaxis place the peptide in innate immune signalling as well as direct antimicrobial work.
Peptide adsorption studies
Its adsorption behaviour makes it a standard test case in work on peptide recovery and container effects.
Handling
Reconstitution and stability
Reconstitution
Reconstitute with sterile or bacteriostatic water added slowly against the inner wall of the vial. Allow the cake to dissolve without agitation, swirling gently if required. Do not vortex or shake.
Stability
Lyophilised at −20 °C, desiccated and protected from light, stable for at least 24 months. Reconstituted and held at 2–8 °C, use within 28 days. Avoid repeated freeze-thaw.
Notes
- Bring the vial to room temperature before opening so atmospheric moisture does not condense onto cold powder.
- Record the reconstitution date on the vial; concentration drift between runs is usually evaporation, not synthesis variance.
- Aliquot at first reconstitution where the working programme needs more than a few withdrawals.
Laboratory reference
Reconstitution calculator
Enter the fill weight on the vial and the diluent volume you intend to add. The calculator returns the resulting solution concentration and the volume that contains a given mass.
- Concentration
- 2.500 mg/mL · 2500 µg/mL
- Volume containing target mass
- 100.0 µL · 0.1000 mL
Figures are mass-to-volume arithmetic for laboratory preparation of LL-37 and take no account of net peptide content, which is stated on the batch certificate and should be applied to the fill weight before calculating. Nothing here constitutes dosing, administration or clinical guidance of any kind.
Published work
What the literature reports
Summaries of published findings, provided as research reference. These describe work done by others in preclinical and clinical settings; they are not claims about this material or outcomes for any reader.
Identification and antimicrobial activity
Characterisation of LL-37 as the processed antimicrobial product of human hCAP18.
Gudmundsson et al., European Journal of Biochemistry, 1996
Immunomodulatory function
Work establishing chemotactic and immunomodulatory roles beyond direct bacterial killing.
De Yang et al., Journal of Experimental Medicine, 2000
Questions
LL-37 — asked and answered
Something not covered here? Ask us directly — technical questions reach someone who runs the assays.
- Why is my recovery so low?
- Almost certainly adsorption. LL-37 is strongly cationic and binds glass and untreated plastic. Use low-binding tubes and tips throughout, and consider a carrier protein if your assay tolerates one.
- Is a carrier protein recommended?
- Where the assay allows it, yes — typically BSA at low percentage. This is an assay design decision and depends on your endpoints.
- What purity is it released at?
- ≥ 98.0% area-percent. At 37 residues, synthesis-related related substances are expected and are itemised on the certificate.
Same class
Others in Immune & Signalling
Important
LL-37 is supplied strictly for laboratory research and analytical use. It is not a medicine, food, cosmetic or veterinary product; it is not for human or animal consumption; and it is not intended to diagnose, treat, cure or prevent any condition. It is not manufactured, tested or released to any standard that would support administration to humans or animals. Information on this page is compiled for research reference and is not medical advice. No dosing, administration or therapeutic guidance is given or implied. By ordering you confirm you are a qualified researcher or institution and accept responsibility for safe handling and lawful use.