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.
Research Applications
Antimicrobial Peptide Research
LL-37 is utilized as a research peptide in studies examining innate immune defense mechanisms and antimicrobial peptide signaling pathways. Laboratory investigations focus on its role in:
- Membrane Interaction Models: Investigation of peptide–lipid membrane binding dynamics and permeability modulation
- Innate Immune Signaling Studies: Evaluation of pathways involved in host defense peptide regulation
- Microbial Interaction Research: Analysis of peptide effects on bacterial and fungal membrane systems under laboratory conditions
- Biofilm Disruption Models: Examination of structural interference with microbial community formation
- Charge-Dependent Binding Studies: Investigation of electrostatic interactions influencing antimicrobial activity
Experimental protocols commonly employ membrane assays, microbial culture systems, and peptide-binding analyses to characterize LL-37–mediated interactions.
Inflammatory and Immune Modulation Research
LL-37 has been extensively studied in research models examining immune signaling modulation and inflammatory pathway regulation. Key areas of investigation include:
- Cytokine Expression Models: Evaluation of inflammatory mediator regulation under peptide exposure
- TLR Signaling Studies: Investigation of Toll-like receptor pathway interactions
- Chemotaxis Research: Analysis of immune cell migration and recruitment mechanisms
- Inflammation Resolution Models: Research into pathways balancing immune activation and regulation
- Adaptive Immune Interaction Studies: Examination of cross-talk between innate and adaptive immune systems
These studies utilize cytokine assays, immune cell culture systems, and transcriptional profiling techniques to evaluate immune-related signaling dynamics.
Dermal and Epithelial Biology Research
LL-37 has also been explored in research models examining epithelial barrier integrity and tissue response mechanisms, including:
- Keratinocyte Activation Studies: Evaluation of epithelial signaling under experimental immune stimulation
- Barrier Integrity Models: Investigation of tight junction regulation and epithelial permeability control
- Angiogenic Signaling Research: Analysis of vascular growth factor pathways in tissue systems
- Wound Environment Interaction Studies: Examination of signaling pathways associated with tissue remodeling
Laboratory protocols assess epithelial signaling, cytokine expression, and structural integrity markers using biochemical and imaging-based techniques.
Cellular Signaling and Host Defense Research
Additional research applications explore LL-37’s influence on intracellular regulatory systems involved in host defense and cellular homeostasis, including:
- MAPK and NF-κB Pathway Studies: Investigation of inflammatory signal transduction cascades
- Gene Expression Profiling: Analysis of transcriptional responses linked to immune activation
- Apoptosis and Cell Survival Models: Research into cellular adaptation during immune stress
- Integrated Immune Feedback Systems: Examination of coordinated signaling networks maintaining host defense equilibrium
Research in this domain focuses on understanding how LL-37 influences membrane interaction mechanisms, immune signaling pathways, and epithelial barrier regulation under controlled experimental conditions.
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.
What is LL-37 commonly researched for?
In laboratory and preclinical models, LL-37 is studied for:
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Antimicrobial activity mechanisms
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Innate immune system signaling
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Cytokine and inflammatory pathway research
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Epithelial barrier function studies
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Wound-healing–related cellular signaling models
All applications are exploratory and conducted in controlled research environments.
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, verifying the identity and purity of each peptide component within the blend 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.
