Title: LL-37 Peptides: Technical Deep Dive, Selection Guide & Brand Comparison
Executive Summary
LL-37 Peptides: technical specs, purity, brands compared. Guide to select optimal antimicrobial peptide for research, with factory certifications & batch data.
Target Keyword: ll 37 pep
Core Molecular Specs & Technical Index
LL-37 peptides, the only cathelicidin-derived antimicrobial peptide found in humans, are a 37-amino-acid, amphipathic, alpha-helical peptide. Researchers and bulk buyers in the cosmetic and biotech sectors rely on this molecule for its broad-spectrum antimicrobial and immunomodulatory properties. The core value lies in its ability to disrupt bacterial membranes while modulating host immune responses, making it a cornerstone in advanced dermatological and infection-control research.
- Molecular Weight: 4493.3 Da (calculated), with a precise sequence of LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES.
- Purity Grade: Standard research grade is ≥95% (HPLC), with premium batches offering ≥98% for sensitive in vivo studies.
- Solubility: Highly soluble in water and PBS (pH 7.4) at concentrations up to 10 mg/mL; avoid repeated freeze-thaw cycles.
- Storage Stability: Lyophilized powder stable for 24 months at -20°C; reconstituted solutions stable for 7 days at 4°C.
- Charge & Structure: Net positive charge (+6) at physiological pH, enabling selective binding to negatively charged bacterial membranes.
Industry data from 2023 shows that LL-37 peptides with ≥98% purity demonstrate 40% higher antimicrobial activity against MRSA compared to batches with 95% purity, emphasizing the critical role of technical specs in research outcomes.
Manufacturing & Quality Control
Production of LL-37 peptides follows solid-phase peptide synthesis (SPPS) using Fmoc chemistry, followed by reverse-phase HPLC purification. Third-party testing via mass spectrometry (MS) and amino acid analysis (AAA) ensures batch-to-batch consistency. Leading factories like Bachem and GenScript provide certificates of analysis (CoA) with each batch, detailing purity, molecular weight, and endotoxin levels.
- Factory Certifications: ISO 9001:2015 for quality management, GMP compliance for cosmetic-grade peptides.
- Batch Data: Typical batch size ranges from 100 mg to 10 g, with custom synthesis available for larger scales.
- Endotoxin Testing: <0.5 EU/mg for in vivo applications; <10 EU/mg for cosmetic formulations.
- Stability Report: Accelerated stability studies confirm 2-year shelf life at -20°C with <2% degradation.
Commercial Application Scenarios
LL-37 peptides are deployed across three primary commercial channels. In cosmetic formulation, they are incorporated into anti-aging serums and acne treatments at concentrations of 0.001% to 0.01% to enhance skin barrier function. In lab research, they serve as positive controls in antimicrobial assays and as tools for studying innate immunity. Bulk wholesale buyers, including pharmaceutical intermediates suppliers, order 1 kg to 10 kg quantities for preclinical trials and custom peptide libraries.
ll 37 peptides VS Ordinary Low-Grade Peptides
| Item | Our Product (LL-37) | Alternatives | Advantages |
|---|---|---|---|
| Purity | ≥98% (HPLC) | 70-85% (crude) | Higher bioactivity, fewer side effects |
| Sequence Accuracy | 100% verified by MS | Often truncated or mis-synthesized | Consistent results in assays |
| Endotoxin Level | <0.5 EU/mg | >10 EU/mg | Suitable for in vivo use |
| Batch Consistency | CV <3% across batches | CV >15% | Reproducible data |
Bulk Purchase Selection Guide
Common pitfalls when sourcing LL-37 peptides include accepting low-purity batches that compromise research validity, ignoring endotoxin levels for in vivo studies, and failing to verify factory certifications. Selection standards demand a minimum of 95% purity for in vitro work and 98% for in vivo applications. Buyer checklist: request CoA for each batch, confirm storage conditions, and ask for stability data. Always choose suppliers with ISO certification and transparent batch records.
Core Product Advantages
Purity: Our LL-37 peptides achieve ≥98% purity via dual HPLC purification, ensuring minimal impurities. Stability: Lyophilized formulation maintains integrity for 24 months at -20°C. Cost Performance: Competitive pricing at $150/mg for 100 mg orders, with volume discounts for 1 g+ quantities. Technical Support: Free consultation on reconstitution protocols and assay design from PhD-level scientists.
Frequently Asked Questions
Q1: What is the recommended purity for LL-37 peptides in cosmetic formulations?
A1: For cosmetic use, ≥95% purity is standard, but ≥98% is preferred to avoid irritation from truncated sequences. Always request an HPLC chromatogram from the supplier.
Q2: How should I reconstitute LL-37 peptides for long-term storage?
A2: Reconstitute in sterile water or PBS at 1 mg/mL, aliquot into single-use vials, and store at -80°C. Avoid freeze-thaw cycles to maintain activity for up to 6 months.
Q3: Can LL-37 peptides be used in combination with other antimicrobial agents?
A3: Yes, LL-37 shows synergistic effects with conventional antibiotics like ciprofloxacin against biofilm-forming bacteria. Test compatibility in your specific assay system before scaling.