Molecular Characteristics
Complete Specifications
Structural Composition
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
Physical Properties
LL-37 is a 37-amino-acid synthetic peptide derived from the human cathelicidin antimicrobial peptide family. Its amphipathic alpha-helical structure contributes to characteristic physicochemical properties under laboratory conditions. The peptide contains multiple positively charged residues, supporting aqueous solubility and interaction with negatively charged biomolecules. Due to its length and structural complexity, proper lyophilized storage and protection from moisture, light exposure, and repeated freeze–thaw cycles are important for maintaining structural integrity and analytical consistency during research applications.
Analysis & Documentation
Identity
Each production lot is checked against the reference structure recorded for this compound:
- Classification — Synthetic 37-amino-acid antimicrobial peptide (cathelicidin family)
- Molecular formula — C₂₀₅H₃₄₀N₆₀O₅₃
- Expected mass — ~4,493.3 Da
- CAS registry — Not assigned (endogenous antimicrobial peptide)
- Chain length — 37 amino acids
- PubChem CID — Not available
Analytical Methods
Testing is carried out per lot by an independent laboratory. The methods measure what the material is and how much of it is the target compound:
- RP-HPLC — reverse-phase separation of the target from process-related impurities; purity is reported as area percent of the main peak
- Mass spectrometry — observed mass compared against the expected molecular mass above
- Retention time — compared against a reference standard run under the same conditions
- Chromatogram — reproduced on the certificate so the peak and any shoulders can be inspected directly
Material & Documentation
What arrives, and how to tie it back to its paperwork:
- Appearance as supplied — White to off-white lyophilized powder
- Solubility — Water, buffered aqueous solutions (e.g., PBS)
- Lot number — printed on the container label and used to look up the certificate
- Certificate — indexed by lot at Certificates of Analysis
Laboratory Handling and Storage Protocols
Lyophilized Powder Storage
- Store at –20°C to –80°C in the original, sealed vial
- Protect from light exposure and moisture
- A desiccated storage environment is recommended
- Stability data suggests extended stability when stored at −20 °C or below.
Reconstituted Solution Storage
- Short-term storage: Up to 7 days at 4°C
- Long-term storage: Store at –20°C in aliquots
- Use single-use aliquots to preserve peptide integrity
- Minimize freeze–thaw cycles; single-use aliquots are strongly recommended
Stability Characteristics
LL-37 is a synthetic antimicrobial peptide research compound that demonstrates stable handling characteristics when managed under standard peptide laboratory protocols. Proper cold storage, careful solvent selection, and minimized mechanical agitation help maintain structural integrity and solubility. When handled appropriately, LL-37 supports consistent use in in vitro and analytical research applications.
Frequently Asked Questions
What is LL-37?
LL-37 is a 37–amino acid synthetic peptide derived from the C-terminal region of the human cathelicidin protein. It is used in research to study host defense mechanisms and immune signaling pathways.
Is LL-37 naturally occurring?
Yes. LL-37 is derived from a naturally occurring human peptide (hCAP-18). Synthetic LL-37 used in research replicates this sequence for experimental study.
Is LL-37 an antibiotic?
No. While LL-37 is studied in antimicrobial pathway research, it is a host defense peptide, not a conventional antibiotic drug.
How is LL-37 supplied?
LL-37 is typically supplied as a lyophilized (freeze-dried) powder in sealed research vials to maintain stability during storage and shipment.
How should unreconstituted LL-37 be stored?
Lyophilized LL-37 should be stored:
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Long-term: −20 °C to −80 °C
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Short-term: 2–8 °C
Keep vials sealed and protected from light and moisture until use.
How should reconstituted LL-37 be handled and stored?
Once reconstituted:
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Store at 2–8 °C for short-term laboratory use
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For extended storage, aliquot and freeze at −20 °C or below
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Minimize freeze–thaw cycles using single-use aliquots
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Gently swirl to mix; avoid vigorous agitation
Does LL-37 require a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis (COA) should be available for each batch of LL-37, verifying identity and purity to ensure research quality and traceability.
Is LL-37 FDA-approved?
No. LL-37 is not FDA-approved as a drug, supplement, or therapeutic product. It is sold exclusively as a research compound and must not be marketed or used for diagnostic, therapeutic, or consumption purposes.
This product is not for human consumption. It is sold strictly for research and educational purposes and is not intended to diagnose, treat, cure, or prevent any disease.
Any clinical data or research information referenced on this page is derived from peer-reviewed scientific literature and official publications. This information is provided for educational reference only and does not constitute medical advice or product claims.
By purchasing this product, you acknowledge that you are a qualified researcher and agree to use it in full compliance with all applicable laws and regulations.
