What is LL-37 5MG

LL-37 5MG is a naturally occurring human antimicrobial peptide (AMP) belonging to the cathelicidin family, studied in research for its broad-spectrum antimicrobial activity and immunomodulatory functions. It is intended exclusively for research use.

Regarding its chemical identity, LL-37 has a molecular formula of C205H340N60O53 and a molecular weight of 4493.3 g/mol. Its reported canonical 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. A confirmed CAS number is not available in open primary reference sources and is therefore omitted.

Its synonyms include LL-37.

Product for research use.

Mechanism of action of LL-37

LL-37 functions primarily by electrostatically binding to the negatively charged cell membranes of bacteria, fungi, and some viruses, creating pores that lead to cell lysis. Additionally, it interacts with formyl peptide receptor-like 1 (FPRL1) on immune cells to induce chemotaxis, angiogenesis, and wound healing.

Pharmacokinetics and pharmacodynamics of LL-37

Endogenous LL-37 is produced locally at sites of infection or inflammation. When administered exogenously in research, it is rapidly degraded by tissue proteases. Its highly cationic, amphipathic nature means it can bind nonspecifically to many biological surfaces.

Scientific evidence on LL-37

The available evidence on LL-37 is preliminary and largely inconclusive, and should be interpreted with caution. The literature describes it as having been investigated for multiple indications in preclinical models.

Investigated extensively as an alternative to traditional antibiotics, particularly against drug-resistant biofilms. It is also studied in the context of chronic wounds, psoriasis, and autoimmune diseases where the dysregulation of LL-37 plays a pathological role.

LL-37 applications in research

Ideal for (research context):
– In vitro and preclinical studies of its specific receptor pathways.
– Investigation of tissue repair, cell proliferation, and functional restoration in laboratory models.
– Comparative work with related peptides.

Not applicable for:
– clinical, diagnostic or therapeutic use.
– Any administration to humans or animals outside of an authorized research protocol.

Product for research use.

LL-37 protocols in preclinical studies

The literature consulted does not include numerical doses from studies that can be cited for LL-37, so no trial schemes or quantities are specified.

The presentations of this product (5MG) refer only to the amount of lyophilized peptide per vial (or volume for liquids) and do not constitute a dosage recommendation. The design of any protocol, including concentrations and working volumes, is the responsibility of the researcher, based on their experimental objectives and the relevant primary literature.

Information provided exclusively for research purposes.

Reconstitution and manipulation of LL-37

As a general guideline for laboratory handling, lyophilized peptides such as LL-37 are usually reconstituted with bacteriostatic water (sterile water with approximately 0.9% benzyl alcohol).

Add the solvent slowly down the side of the vial, letting it run over the lyophilized powder; avoid injecting the stream directly onto the powder.
Do not shake: gently rotate the vial until completely dissolved.
Adjust the solvent volume according to the desired working concentration, considering the 5MG contents of the vial.

These guidelines are for general technique and do not replace the internal procedures of each laboratory.

LL-37 Stability and Storage

As a standard laboratory handling procedure for peptides:

Freeze-dried (unreconstituted): This is the most stable form. It is best preserved by freezing and protecting it from moisture and light for long-term storage.
Reconstituted: once in solution, the peptide is less stable and must be kept refrigerated, being used within a short period; for extended storage, freezing in aliquots is usually preferred.
Avoid repeated freeze-thaw cycles, as they can degrade the peptide.

Given that the molecule is characterized by rapid enzymatic degradation in biological media, careful cold chain management is especially relevant.

Documented LL-37 security profile

The documented safety information in open sources for LL-37 is limited and should be interpreted with caution, also considering that it is research material and not for clinical use.

At high concentrations, LL-37 can exhibit cytotoxicity to mammalian cells (e.g., erythrocytes and leukocytes) due to membrane disruption. Systemic administration can hypothetically cause widespread inflammation or autoimmune triggering in susceptible models.

Formal contraindications and adverse event rates are not available in the consulted literature, so no figures are reported.

LL-37 in a comparative context

Unlike traditional small-molecule antibiotics that target specific bacterial enzymes, LL-37 physically destroys microbial membranes, making resistance much harder to develop. It is the only human cathelicidin, distinguishing it from defensins.

History and development of LL-37

Discovered in 1995 as the 37-amino-acid C-terminal peptide cleaved from the human CAP18 protein. It remains a major focus of immunology and infectious disease research as a potential template for novel antimicrobial therapies.