LL-37 Peptide

LL-37 Peptide (Human Cathelicidin)

Welcome to buypeptidesonlineusa.com, your premier domestic source for high-purity research peptides. Our LL-37 peptide is the synthetic 37-amino acid version of the only human cathelicidin antimicrobial peptide (AMP). It is a multifunctional host defense peptide, meticulously manufactured for advanced investigations into innate immunity, infectious disease models, wound healing, immunomodulation, and oncology research. As a key effector molecule of the immune system, LL-37 is an essential tool for researchers exploring novel therapeutic strategies against multidrug-resistant pathogens and chronic inflammatory conditions. We ensure your critical research is supported by uncompromising quality, transparency, and rapid fulfillment.

🚚 FREE SHIPPING ON ORDERS OVER $300 | 🔐 SECURE CHECKOUT & DISCREET PACKAGING

⚠️ Important Research Compliance Notice

This product is intended strictly for laboratory research use only and is not for human consumption or veterinary use. This product is not a medicine, drug, or medical device. It has not been evaluated by the FDA. This peptide is sold for investigational purposes by qualified researchers and professionals only.

🔬 What is LL-37 Peptide?

LL-37 is a synthetic 37-amino acid peptide corresponding to the C-terminal region of the only known human cathelicidin protein, hCAP18 . Its name derives from its sequence, which begins with two leucine (L) residues, and its total length of 37 amino acids. The full sequence is: Leu-Leu-Gly-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gly-Lys-Glu-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-Asn-Leu-Val-Pro-Arg-Thr-Glu-Ser .

As a member of the cathelicidin family, LL-37 is a key effector molecule of the innate immune system. It is produced by various cell types, including neutrophils, epithelial cells, and macrophages, and is stored as a proprotein (hCAP18) that is cleaved to release the active LL-37 peptide. Its multifaceted roles include:

• Direct Antimicrobial Activity: LL-37 exhibits broad-spectrum activity against Gram-positive and Gram-negative bacteria, fungi, parasites, and enveloped viruses. It is known to be effective against over 38 bacterial strains and 16 fungal species . Its mechanism often involves disrupting microbial membranes due to its cationic and amphipathic structure .
• Immunomodulation: Beyond direct killing, LL-37 acts as a "alarmin," modulating the immune response. It can chemoattract immune cells, regulate cytokine production, promote angiogenesis, and influence both pro- and anti-inflammatory pathways .
• Wound Healing: LL-37 promotes wound healing by stimulating cell proliferation, migration, and angiogenesis. It also enhances re-epithelialization and modulates the inflammatory phase of wound repair .
• Antitumor Activity: Research suggests LL-37 and its fragments possess tumor-active properties, demonstrating cytotoxicity against certain cancer cell lines, such as HeLa cells, in vitro .

✅ Why Choose Buy Peptides Online USA for Your Research?

When you need to buy LL-37 peptide online, quality and consistency are non-negotiable. Here is why discerning researchers choose us:

• Verified Purity: We provide access to independent third-party Certificate of Analysis (COA) documents, confirming purity via High-Performance Liquid Chromatography (HPLC) exceeding 95% and identity via Mass Spectrometry (MS) .
• Optimal Storage & Handling: Our LL-37 is shipped in lyophilized form. For long-term stability, store desiccated at -20°C or below, protected from light and moisture .
• Domestic Shipping: As a USA-based supplier, we offer fast, reliable shipping. Orders typically arrive within 2-5 business days in discreet, temperature-controlled packaging.
• Research-Focused: We make no medical claims. Our service is built on integrity, providing accurately labeled products for legitimate scientific inquiry.
• Secure Transactions: Enjoy peace of mind with secure checkout and multiple payment options, including credit cards and cryptocurrency.

🔎 Product Specifications & Technical Data

To ensure your research parameters are met with precision, here are the verified technical specifications for our LL-37 peptide. Purity is a critical determinant of research accuracy, and our product meets the high standards expected by the scientific community.

🧪 Key Research Applications & Focus Areas

LL-37's multifunctional nature makes it a powerful and versatile tool across a wide spectrum of biomedical research.

• 🦠 Antimicrobial & Infectious Disease Research: LL-37 is a cornerstone tool for studying host defense against pathogens. It is used to investigate its direct antimicrobial effects against a wide array of multidrug-resistant (MDR) bacteria, fungi, and viruses . Its mechanisms of action, including membrane disruption, cell wall targeting, and biofilm inhibition, are key areas of study . Research also focuses on its antiviral properties against pathogens like Ebola virus .

• 🩹 Wound Healing & Regenerative Medicine: LL-37 is extensively studied for its role in tissue repair. It promotes keratinocyte and fibroblast migration and proliferation, accelerates wound closure, and modulates angiogenesis . Recent 2025 research explores advanced delivery systems, such as PLGA nanocarriers, to enhance LL-37's stability and controlled release for improved wound healing applications .

• 🛡️ Immunology & Inflammation Research: As an alarmin and immunomodulator, LL-37 is used to study its complex effects on the immune system. It can chemoattract immune cells like neutrophils and T-cells, modulate the release of cytokines and chemokines, and influence both inflammatory and anti-inflammatory responses . It is a key tool for understanding the interplay between innate and adaptive immunity.

• 🧬 Cancer Research (Oncology): LL-37 and its fragments have demonstrated cytotoxic activity against tumor cells . For example, the GF-17 fragment (LL-37 15-32) has shown cytotoxicity against HeLa (cervical cancer) cells . Researchers use LL-37 to investigate its potential as a template for designing novel anticancer peptides (ACPs) and to study its role in the tumor microenvironment.

• 🧪 Peptide Engineering & Drug Design: Due to its therapeutic potential but limitations like proteolytic sensitivity and cytotoxicity at high concentrations, LL-37 is a model peptide for engineering studies . Research focuses on creating truncated analogs (e.g., GF-17, KR-20), retro-inverso versions, and lipidized forms to enhance stability, reduce toxicity, and improve efficacy for potential clinical translation .

📝 Handling, Storage, and Preparation for Research

Proper handling is critical to maintaining peptide integrity and ensuring experimental validity.

• Receiving & Storage: Upon receipt, store the lyophilized vial in a freezer at -20°C (-4°F) or below. Protect from light and moisture . Allow the vial to reach room temperature in a desiccator before opening to prevent moisture absorption.
• Reconstitution: To prepare stock solutions, LL-37 is soluble in sterile water or sterile buffer . Briefly centrifuge the vial to concentrate the lyophilized powder at the bottom before opening. Gently swirl or invert to dissolve; do not vortex, as this can cause foaming and denaturation.
• Dosage Considerations:
  • In vitro: Effective concentrations vary widely depending on the assay. Antimicrobial activity is often observed in the low micromolar (µM) range (e.g., 1-10 µM). Cytotoxicity studies on cancer cells have reported 50% cytotoxicity at concentrations like 30 µM .
  • In vivo (Rodent): Doses for wound healing or infection models must be determined empirically based on literature and IACUC guidelines. Novel delivery systems like nanoparticles are being developed to optimize in vivo efficacy .
• Preventing Adsorption: At low concentrations, peptides can adsorb to plastic surfaces. Using low-protein-binding tubes and siliconized tips is recommended. Adding a carrier protein (e.g., 0.1% BSA) to the dilution buffer can also help.
• Safety & Handling: Always use personal protective equipment (PPE) such as gloves and safety goggles when handling. Work in a laminar flow hood or well-ventilated area. Dispose of all waste in appropriate biohazard containers.

❓ Frequently Asked Questions (FAQ)

Q1: What is the difference between LL-37 and hCAP18?

A: hCAP18 (human Cationic Antimicrobial Protein of 18 kDa) is the full-length precursor protein that is stored in cells. It must be cleaved by proteinases to release the active LL-37 peptide, which is the C-terminal 37-amino acid fragment responsible for most of its biological activities.

Q2: What is the primary mechanism of LL-37's antimicrobial action?

A: LL-37 is a cationic amphipathic peptide, meaning it has both positive charges and a hydrophobic region. This allows it to interact with and insert into the negatively charged membranes of many microbes, leading to membrane disruption and cell lysis . It can also act on intracellular targets and inhibit biofilm formation.

Q3: How do I verify the quality of your LL-37?

A: We are committed to transparency. Our product listings provide access to a third-party Certificate of Analysis (COA) . This document validates the compound's identity via Mass Spectrometry (MS) and its purity via High-Performance Liquid Chromatography (HPLC), which is ≥95% .

Q4: What are the main challenges in LL-37 research?

A: While highly promising, LL-37 research faces challenges including its susceptibility to proteolytic degradation, potential cytotoxicity at high concentrations, and high production costs. Much of the current research focuses on developing modified analogs and novel delivery systems to overcome these hurdles .

Q5: How should I store LL-37 after reconstitution?

A: It is essential to aliquot the reconstituted solution into single-use vials to avoid repeated freeze-thaw cycles, which degrade the peptide. Store aliquots at -20°C or below and use them within one month for optimal stability .

📦 Our Services & Guarantees

• 24/7 Customer Support: Our team is available to answer your pre- and post-sales questions.
• Authenticity Guarantee: We guarantee that you receive the exact product described, with full documentation and lot matching.
• Product Replacement: In the unlikely event of damage during shipping, we have a clear process for claims and replacement.
• Technical Consultation: Contact us for assistance with solubility or handling protocols.

🚀 How to Buy LL-37 Peptide Online

Purchasing from buypeptidesonlineusa.com is simple and secure.

1. Browse & Select: Choose the quantity you need (e.g., 200 µg, 500 µg, 1mg vial).
2. Add to Cart: Proceed to our secure checkout.
3. Payment: We accept major credit cards and cryptocurrency (Bitcoin, Ethereum, USDT) for privacy and convenience.
4. Shipping: Orders are processed within 24 hours on business days and shipped in discreet, temperature-controlled packaging. Domestic orders typically arrive in 2-5 days.

Ready to advance your innate immunity and infection research? Add high-purity LL-37 peptide (Human Cathelicidin) to your cart today.