LL-37 5mg

LL-37 5 mg is a synthetic cathelicidin-derived peptide research compound supplied by Grail Formula for scientific investigation and controlled laboratory experimentation involving antimicrobial peptide biology, innate immune signalling, peptide-membrane interactions and cellular defence-associated molecular pathways.

LL-37 is a 37-amino-acid cationic peptide investigated in molecular microbiology, peptide biochemistry, membrane biophysics and experimental immunology. Its amphipathic structure and relationship with the cathelicidin peptide family make it an important subject in the study of host defence peptides and their molecular interactions.

This preparation is supplied as a nominal 5 mg peptide research material with independent batch-specific analytical documentation from Liquilabs s.r.o., Czechia.

For research use only — not for human or veterinary use.

 

Product Overview

LL-37 is a synthetic research peptide corresponding to a 37-amino-acid sequence associated with the human cathelicidin antimicrobial peptide system. It is widely investigated in laboratory research involving peptide-membrane interactions, innate immune-associated signalling and antimicrobial peptide structure-function relationships.

The peptide is characterised by its cationic and amphipathic molecular properties, which are relevant to experimental investigations involving lipid membranes, microbial model systems and biochemical interactions between peptides and cellular components.

Grail Formula supplies LL-37 5 mg as a nominal 5 mg peptide research preparation intended exclusively for controlled laboratory and in vitro scientific experimentation.

Independent third-party analytical testing was conducted by Liquilabs s.r.o., Czechia. The Certificate of Analysis, published on 11 October 2026, identifies production batch GF-LL375-B242 and laboratory sample LYO-1003.

The analytical report documents a measured LL-37 assay content of 7.12 mg ± 0.04 mg and chromatographic purity of greater than 99.8 %.

The measured assay content exceeds the nominal 5 mg designation by 2.12 mg, representing a positive difference of 42.4 %. This substantial difference is disclosed separately from the chromatographic purity result.

The Certificate of Analysis also includes FTIR spectrum identification, retention time assessment, molecular ion mass identification, bacterial endotoxin testing, microbiological counts and elemental impurity screening.

These measurements provide batch-specific analytical information about the tested peptide preparation. They do not independently establish antimicrobial activity, biological potency, functional effects in cellular systems or suitability for administration.

 

Peptide Overview

LL-37 is a 37-amino-acid peptide belonging to the cathelicidin family of host defence peptides, a group of molecules investigated for their involvement in innate immune-associated molecular processes.

The LL-37 sequence is derived from the C-terminal region of the human cathelicidin precursor protein hCAP18, which is encoded by the CAMP gene.

Proteolytic processing of cathelicidin precursor proteins is an important subject in peptide biology because it illustrates how larger protein structures can generate shorter molecular sequences with distinct biochemical characteristics.

LL-37 is distinguished by its positively charged amino acid composition and amphipathic structure, which contribute to its scientific relevance in membrane interaction studies.

Under appropriate experimental conditions, LL-37 can adopt an alpha-helical conformation that presents hydrophobic and positively charged regions on different surfaces of the peptide.

This structural arrangement is investigated in relation to interactions with lipid bilayers, negatively charged membrane components and model membrane systems.

Research involving LL-37 extends beyond membrane biophysics into molecular microbiology and experimental studies of innate immune-associated signalling pathways.

Scientists investigate the peptide in relation to microbial membrane models, cellular signalling intermediates, peptide-lipid interactions and experimental host defence mechanisms.

LL-37 has also been examined in studies involving extracellular nucleic acids, molecular recognition processes and inflammatory signalling in laboratory models.

These research areas contribute to understanding how peptide structure, charge distribution and environmental conditions influence molecular interactions.

However, experimentally observed responses depend on the biological model, peptide concentration, membrane composition and analytical conditions employed.

Findings from published experimental research should not be interpreted as independently demonstrated biological properties of the Grail Formula LL-37 5 mg preparation.

The Liquilabs Certificate of Analysis identifies a molecular ion mass of 4493 Da ± 1 Da, providing an identity-related analytical measurement for the tested peptide.

This molecular mass result is distinct from the measured assay content of 7.12 mg and the chromatographic purity of greater than 99.8 %.

 

Historical Background and Scientific Context

Scientific investigation of antimicrobial peptides developed from research into naturally occurring molecular components associated with innate defence systems.

Early studies identified various peptide families with distinct amino acid compositions, molecular structures and biochemical interactions with microbial model systems.

Among these families, cathelicidins attracted scientific interest because of their conserved precursor organisation and the diversity of peptide sequences generated through proteolytic processing.

The identification of human cathelicidin-related peptides contributed to a broader understanding of host defence peptide biology and the molecular characteristics of positively charged peptide sequences.

LL-37 became a prominent research subject because of its 37-amino-acid structure and its relationship with the C-terminal region of the hCAP18 precursor protein.

Researchers subsequently examined its molecular conformation, amphipathic properties and interactions with artificial lipid membranes.

Advances in structural biology and membrane biophysics enabled more detailed investigation of how cationic peptides interact with lipid bilayers and other molecular assemblies.

Experimental methods such as circular dichroism spectroscopy, fluorescence-based membrane assays and molecular modelling contributed to the characterisation of LL-37-associated structural behaviour.

Scientific research also expanded toward examining LL-37 in relation to intracellular signalling pathways and interactions with molecular components involved in innate immune-associated responses.

These investigations included laboratory studies involving microbial models, cellular signalling systems and biochemical interactions with extracellular molecules.

As peptide synthesis technology advanced, synthetic LL-37 preparations became relevant to controlled laboratory investigations requiring defined peptide sequences.

Analytical chemistry methods subsequently improved the ability to characterise synthetic peptide materials through chromatographic purity assessment, quantitative peptide assay and molecular identity testing.

Ultra-high-performance liquid chromatography and mass spectrometry provide complementary information about peptide composition and molecular characteristics.

Chromatographic purity describes the relative composition measured under defined analytical conditions, while quantitative assay measurements estimate the amount of the target peptide present in a tested sample.

These measurements are not interchangeable and must be interpreted separately when reviewing batch-specific analytical documentation.

Contemporary LL-37 research continues to examine peptide structure, membrane interactions, molecular microbiology and innate immune-associated signalling within controlled experimental systems.

 

Mechanistic Focus in Research

The principal mechanistic research interest surrounding LL-37 concerns its cationic amphipathic structure and its interactions with lipid membranes, molecular recognition systems and innate immune-associated biochemical pathways.

Peptide-membrane interactions

LL-37 is investigated in membrane biophysics because its positively charged and amphipathic structure can participate in interactions with lipid assemblies under defined experimental conditions.

Researchers examine how peptide charge distribution, lipid composition and environmental conditions influence peptide association with model membranes.

Experimental investigations may use synthetic lipid vesicles, supported lipid bilayers and fluorescence-based analytical techniques to characterise these interactions.

Antimicrobial peptide structure-function relationships

LL-37 is an important research model for examining relationships between amino acid sequence, peptide conformation and molecular interactions with microbial membrane systems.

Laboratory studies investigate how structural features such as charge, hydrophobicity and alpha-helical organisation influence peptide behaviour.

These investigations contribute to broader scientific understanding of cationic host defence peptides and their biochemical characteristics.

Innate immune-associated molecular signalling

LL-37 has been investigated in experimental systems involving molecular pathways associated with innate immune regulation.

Research may examine interactions with cellular signalling intermediates, pattern-recognition-associated pathways and other molecular components involved in experimental immune signalling.

The direction and magnitude of observed responses depend on the cellular model, experimental environment and analytical endpoints.

Peptide interactions with nucleic acids

Experimental studies have examined LL-37 in relation to interactions with extracellular DNA and RNA.

These investigations contribute to understanding how cationic peptides may associate with negatively charged nucleic acid structures under controlled laboratory conditions.

Researchers may investigate peptide-nucleic acid complex formation, molecular stability and associated biochemical signalling responses.

Membrane composition and peptide selectivity

The lipid composition of experimental membranes can influence peptide binding and molecular interactions.

LL-37 is investigated in comparative membrane studies involving different lipid compositions, surface charges and physicochemical environments.

Such investigations provide a scientific context for examining how peptide structure and membrane characteristics contribute to observed molecular behaviour.

Peptide conformation and analytical characterisation

LL-37 is also relevant to research involving peptide secondary structure, chromatographic separation and molecular mass determination.

Analytical techniques such as UHPLC and mass spectrometry provide information about the chemical characteristics of synthetic peptide preparations.

The supplied Liquilabs Certificate of Analysis documents chromatographic purity, quantitative assay content, FTIR spectrum identification, retention time assessment and molecular ion mass identification.

However, the report does not contain antimicrobial susceptibility assays, membrane disruption measurements, receptor activation experiments or other biological activity testing.

Accordingly, the mechanistic research topics described above represent scientific research areas associated with LL-37 rather than experimentally confirmed functional properties of batch GF-LL375-B242.

 

Analytical Verification (COA)

Grail Formula provides independent batch-specific analytical documentation through testing conducted by Liquilabs s.r.o., Czechia.

The Certificate of Analysis for LL-37 5 mg was published on 11 October 2026 and identifies production batch GF-LL375-B242, laboratory sample LYO-1003.

The 13-page report includes peptide assay results, chromatographic purity assessment, FTIR spectrum identification, retention time assessment, mass spectrometry, bacterial endotoxin testing, microbiological counts and elemental impurity screening.

Peptide assay and chromatographic purity

• Nominal product quantity: 5 mg
• Measured LL-37 assay content: 7.12 mg ± 0.04 mg
• Reported chromatographic purity: greater than 99.8 %
• Measured assay difference from nominal quantity: 2.12 mg above the labelled 5 mg
• Measured assay as a proportion of nominal quantity: 142.4 %
• Analytical screening designation: Peptide Screening 0.1% TFA

The measured assay content exceeds the nominal quantity by 42.4 %. This substantial positive difference is a batch-specific analytical finding and is disclosed independently of the chromatographic purity result.

The reported purity of greater than 99.8 % describes the chromatographic composition under the applied analytical conditions. It does not mean that greater than 99.8 % of the nominal 5 mg quantity was recovered.

The supporting analytical documentation includes UHPLC method specifications, calibration information and chromatographic records relating to peptide content and purity assessment.

Peptide identity assessment

• FTIR spectrum identification result: 948 ± 5, as reported
• Retention time identification result: 0.997 ± 0.005, as reported
• Molecular ion mass identification: 4493 Da ± 1 Da
• Mass spectrometry identity assessment: MS deconvolution

The Certificate of Analysis includes chromatographic and mass spectrometric documentation supporting the analytical characterisation of the tested peptide.

The FTIR spectrum and retention time identification values are reproduced as reported. The summary does not provide separate explicit pass/fail interpretations for these measurements.

The molecular ion mass of 4493 Da is an identity-related analytical result and is distinct from the measured peptide assay content expressed in milligrams.

Bacterial endotoxin assessment

• Bacterial endotoxin: 0.012 EU/mg
• Reported uncertainty: ± 0 EU/mg
• Laboratory acceptable range: 0–0.5 EU/mg
• Analytical reference: USP <85> / European Pharmacopoeia 2.6.14
• Method: Chromogenic bacterial endotoxin testing

The bacterial endotoxin concentration of 0.012 EU/mg falls within the laboratory’s stated acceptable range.

This is a measurable analytical result and should not be represented as the complete absence of bacterial endotoxins.

The laboratory’s stated uncertainty of ± 0 is reproduced as reported and should not be interpreted as proof of absolute measurement precision.

The endotoxin result does not establish sterility, biological safety or suitability for administration.

Microbiological assessment

• Total aerobic microbial count: 0 CFU/g
• Total yeast and mould count: 0 CFU/g
• Reported aerobic microbial count range: 0–1000 CFU/g
• Reported yeast and mould count range: 0–100 CFU/g
• Analytical reference: USP <61> / European Pharmacopoeia 2.6.12
• Method: Plate-count testing

Both microbiological counts were reported as zero under the applied laboratory testing conditions.

These findings apply to the tested sample and do not demonstrate the absence of every possible microorganism.

Elemental impurity screening

Seven elemental impurities were evaluated using procedures referenced to USP <232> and European Pharmacopoeia 5.20 / 2.4.20.

• Arsenic: below 0.001 ppm
• Cadmium: below 0.001 ppm
• Mercury (listed as quicksilver): below 0.001 ppm
• Lead: below 0.001 ppm
• Nickel: below 0.001 ppm
• Vanadium: below 0.001 ppm
• Cobalt: below 0.001 ppm

All seven reported elemental impurity concentrations were below 0.001 ppm and within their respective laboratory acceptable ranges.

Results below the analytical reporting threshold indicate concentrations below that threshold rather than confirmation of absolute absence.

The complete Certificate of Analysis contains 13 pages of analytical findings and supporting documentation, including chromatographic records, mass spectrometric data, endotoxin determination information and microbiological testing methodology.

The reported findings relate exclusively to the tested sample and should not automatically be applied to unrelated production batches.

 

Research Applications

LL-37 is investigated in experimental molecular microbiology, peptide biochemistry, membrane biophysics and innate immune-associated molecular signalling research.

Its scientific relevance arises from its cathelicidin-related origin, amphipathic structure and investigated interactions with lipid membranes and molecular signalling systems.

Potential areas of laboratory investigation include:

• Cathelicidin and host defence peptide research
• Antimicrobial peptide structure-function investigations
• Experimental peptide-membrane interaction studies
• Model lipid bilayer and membrane biophysics research
• Innate immune-associated molecular signalling investigations
• Peptide interactions with extracellular nucleic acids
• Comparative studies of cationic amphipathic peptides
• Peptide secondary structure and molecular conformation research
• Chromatographic purity and quantitative peptide analysis
• Mass spectrometric peptide identity assessment

These applications describe scientific research directions rather than demonstrated biological activity of the tested batch.

Experimental investigations require appropriate analytical controls, suitable reference materials and validated methods for evaluating peptide-associated biochemical responses.

Batch-specific Certificate of Analysis documentation can support laboratory recordkeeping and provide researchers with information about the measured characteristics of the preparation.

 

Grail Formula Quality

Grail Formula focuses on supplying laboratory research compounds supported by transparent product information and independently documented analytical findings.

For LL-37 5 mg, Liquilabs testing provides batch-specific information concerning peptide assay content, chromatographic purity, analytical identity, bacterial endotoxin concentration, microbiological counts and selected elemental impurities.

The report documents a measured assay content of 7.12 mg against the nominal 5 mg quantity, chromatographic purity greater than 99.8 % and bacterial endotoxin concentration of 0.012 EU/mg.

These measurements are presented separately to maintain a clear distinction between peptide quantity, chromatographic composition and microbiological characteristics.

The substantial positive assay difference of 42.4 % is disclosed transparently as part of the batch-specific analytical profile.

Each result should be interpreted within the scope of the tested sample, the applied laboratory methodology and the reported measurement uncertainty.

 

When You Choose Grail Formula

Grail Formula provides LL-37 5 mg with independent batch-specific analytical documentation from Liquilabs s.r.o., Czechia.

Researchers can review the Certificate of Analysis to examine the reported peptide assay, chromatographic purity, FTIR spectrum identification, retention time assessment, molecular ion mass, microbiological findings and elemental impurity results.

The report identifies the production batch, laboratory sample and publication date, supporting analytical traceability and laboratory documentation.

Grail Formula emphasises factual scientific descriptions, transparent reporting and clear distinctions between analytical measurements and biological properties that have not been established.

For laboratory research involving cathelicidin peptides, membrane biophysics and molecular microbiology, this documentation provides a reference for the measured characteristics of the tested LL-37 preparation.

Research Use Limitation

Used solely for in vitro experiments and cannot be:

• Used in clinical trials involving humans
• Administered to humans as part of an experiment or investigation
• Supplied to another party for human investigational use.

• Independently analysed by Liquilabs s.r.o. Czechia
• LL-37 cathelicidin-derived peptide research compound with nominal 5 mg quantity
• Chromatographic purity greater than 99.8 % reported by COA
• Assay content measured at 7.12 mg ± 0.04 mg
• Measured assay content 42.4 % above nominal quantity
• Identification evaluated by FTIR spectrum and retention time analysis
• FTIR spectrum identification result: 948 ± 5
• Retention time identification result: 0.997 ± 0.005
• Molecular ion mass identified at 4493 Da ± 1 Da
• Bacterial endotoxin level of 0.012 EU/mg
• Total aerobic microbial count: 0 CFU/g
• Total yeast and mould count: 0 CFU/g
• All seven reported elemental impurities below 0.001 ppm
• Batch number: GF-LL375-B242
• Laboratory sample identification: LYO-1003
• COA publication date: 11 October 2026
• Independent 13-page batch-specific Certificate of Analysis
• Investigated in cathelicidin peptide and membrane interaction research
• Relevant to controlled laboratory studies involving antimicrobial peptide biochemistry
• For research use only – not for human or veterinary use

For laboratory research only. Not intended for human consumption, injection, or cosmetic use.

This product is for research purposes only. Not for human use or diagnostic/therapeutic applications. Keep out of reach of children.