biohacking$bioLLM CA: TBA

database / immune

LL-37

also known as cathelicidin antimicrobial peptide

preclinical immune immuneintegumentary no independent mass to check against

Research reference only. The observations below are recorded in the cited literature. Nothing here is advice or a recommendation, and no dosing information is published on this site.

Sequence

LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

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

1. Leu — Leucine · hydrophobic · hydropathy 3.8 · charge 0L12. Leu — Leucine · hydrophobic · hydropathy 3.8 · charge 0L3. Gly — Glycine · glycine · hydropathy -0.4 · charge 0G4. Asp — Aspartic acid · negative · hydropathy -3.5 · charge −1D5. Phe — Phenylalanine · aromatic · hydropathy 2.8 · charge 0F6. Phe — Phenylalanine · aromatic · hydropathy 2.8 · charge 0F67. Arg — Arginine · positive · hydropathy -4.5 · charge +1R8. Lys — Lysine · positive · hydropathy -3.9 · charge +1K9. Ser — Serine · polar · hydropathy -0.8 · charge 0S10. Lys — Lysine · positive · hydropathy -3.9 · charge +1K11. Glu — Glutamic acid · negative · hydropathy -3.5 · charge −1E1112. Lys — Lysine · positive · hydropathy -3.9 · charge +1K13. Ile — Isoleucine · hydrophobic · hydropathy 4.5 · charge 0I14. Gly — Glycine · glycine · hydropathy -0.4 · charge 0G15. Lys — Lysine · positive · hydropathy -3.9 · charge +1K16. Glu — Glutamic acid · negative · hydropathy -3.5 · charge −1E1617. Phe — Phenylalanine · aromatic · hydropathy 2.8 · charge 0F18. Lys — Lysine · positive · hydropathy -3.9 · charge +1K19. Arg — Arginine · positive · hydropathy -4.5 · charge +1R20. Ile — Isoleucine · hydrophobic · hydropathy 4.5 · charge 0I21. Val — Valine · hydrophobic · hydropathy 4.2 · charge 0V2122. Gln — Glutamine · polar · hydropathy -3.5 · charge 0Q23. Arg — Arginine · positive · hydropathy -4.5 · charge +1R24. Ile — Isoleucine · hydrophobic · hydropathy 4.5 · charge 0I25. Lys — Lysine · positive · hydropathy -3.9 · charge +1K26. Asp — Aspartic acid · negative · hydropathy -3.5 · charge −1D2627. Phe — Phenylalanine · aromatic · hydropathy 2.8 · charge 0F28. Leu — Leucine · hydrophobic · hydropathy 3.8 · charge 0L29. Arg — Arginine · positive · hydropathy -4.5 · charge +1R30. Asn — Asparagine · polar · hydropathy -3.5 · charge 0N31. Leu — Leucine · hydrophobic · hydropathy 3.8 · charge 0L3132. Val — Valine · hydrophobic · hydropathy 4.2 · charge 0V33. Pro — Proline · proline · hydropathy -1.6 · charge 0P34. Arg — Arginine · positive · hydropathy -4.5 · charge +1R35. Thr — Threonine · polar · hydropathy -0.7 · charge 0T36. Glu — Glutamic acid · negative · hydropathy -3.5 · charge −1E3637. Ser — Serine · polar · hydropathy -0.8 · charge 0S37

No independent molecular weight was available to check the sequence against.

Molecular data

Chemical fields come from the PubChem compound record; computed values are derived from the sequence shown above.
molecular formulanot characterised
molecular weight4493.32 Da (computed from sequence)
computed backbone mass4493.32 Da
length37 residues
net charge (pH 7.4)+6
mean hydropathy-0.72
half-lifenot characterised
delivery routenot characterised
PubChem CIDnot characterised
PDB2K6O
UniProt parentP49913

Mechanism

Human cathelicidin-derived antimicrobial peptide; forms an amphipathic helix that disrupts microbial membranes.

Reported targets: microbial membranes FPR2

Experimental structure

α-carbon backbone trace rendered from the deposited coordinates of PDB 2K6O. This is measured structure, not a prediction.

Helical wheel

1. Leu — Leucine · hydrophobicL2. Leu — Leucine · hydrophobicL3. Gly — Glycine · glycineG4. Asp — Aspartic acid · negativeD5. Phe — Phenylalanine · aromaticF6. Phe — Phenylalanine · aromaticF7. Arg — Arginine · positiveR8. Lys — Lysine · positiveK9. Ser — Serine · polarS10. Lys — Lysine · positiveK11. Glu — Glutamic acid · negativeE12. Lys — Lysine · positiveK13. Ile — Isoleucine · hydrophobicI14. Gly — Glycine · glycineG15. Lys — Lysine · positiveK16. Glu — Glutamic acid · negativeE17. Phe — Phenylalanine · aromaticF18. Lys — Lysine · positiveK

Residues projected at 100° per turn, the standard α-helix rotation. Shown because helicity in this peptide is described in the cited literature.

Position in the parent protein

exact match at residues 134–170 of Cathelicidin antimicrobial peptide (170 aa)

…GTVTLNQARGSFDISCDKDNKRFALLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

Parent sequence from UniProt P49913. LL-37 is the mature C-terminal peptide of hCAP18.

Reported effects

Each row is an outcome described in the literature indexed for this peptide. Reported in the cited work — not a claim, not a recommendation.

Reported observations and the corpus they are drawn from.
reported outcomewhere it appears
antimicrobial activityImpact of cathelicidin cleavage by SpeB on <i>Streptococcus pyogenes</i> C… bioRxiv 2026
wound healing in modelsCombinatorial therapy of LL-37 and ADSCs accelerates diabetic wound repair b… Cytokine 2026
immune modulationAntibiotic loaded solid lipid nanoparticles target bacteria in a pyogenic sp… Discover nano 2026

Registered trials

Records from ClinicalTrials.gov. Listed for reference — this project sponsors no trial and is not involved in any of them.
NCTtitlestatusphase
NCT07496710Relationship Between Nutritional Status, Physical Activity and Periodontal StatusCOMPLETED—
NCT05054361Crosstalk Between Mucosal-Associated Invariant T (MAIT) Cells and the Gut Microbiota and MucRECRUITING—
NCT02058407A Study to Evaluate the Safety, Tolerability, Pharmacokinetics (PK), Pharmacodynamics (PD) aTERMINATEDPHASE1
NCT05969275Umbilical Mesenchymal Stromal Cells as Cellular Immunotherapy for Septic ShockRECRUITINGPHASE2
NCT06867250Peri-implant Vitamin D and Cathelicidin (LL-37) LevelsCOMPLETED—

Literature (8)

Impact of cathelicidin cleavage by SpeB on <i>Streptococcus pyogenes</i> CovRS signaling — bioRxiv 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · DOI 10.64898/2026.08.12.744433

Combinatorial therapy of LL-37 and ADSCs accelerates diabetic wound repair by orchestrating NRROS-mediated crosstalk between TGF-β/SMAD and hippo/TEAD1 axes — Cytokine 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · PMID 42641316 · DOI 10.1016/j.cyto.2026.157203

Antibiotic loaded solid lipid nanoparticles target bacteria in a pyogenic spondylitis rat model — Discover nano 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · PMID 42560613 · DOI 10.1186/s11671-026-04853-7

Melanoma exosomal hsa-miR-221-5p suppresses keratinocyte LL-37 to promote tumor progression — Cell reports 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · PMID 42593966 · DOI 10.1016/j.celrep.2026.117837

Targeted delivery of antimicrobial peptide LL-37 via ferritin fusion improves antibacterial and anti-inflammatory outcomes in a murine sepsis model — International journal of biological macromolecules 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · PMID 42669340 · DOI 10.1016/j.ijbiomac.2026.154251

LL-37 IgG levels are associated with clinical characteristics and T follicular cell response in acute coronary syndrome in adults — Physiological reports 2026

Elevated LL-37 IgG levels are implicated in inflammatory conditions and immune complexes formed with LL-37 potentially propagate immunothrombosis in acute coronary syndrome (ACS). The reported binding of LL-37 to LDL may be relevant in this context given that LDL autoantibodies are implicated in ACS risk. In this report, three distinct cohorts were used to evaluate immunologic characteristics, clinical relevance, and potential mechanisms of elevated LL-37 IgG levels in ACS. First, evaluation of IgG reactive to native (n) LDL and LL-37 complexed with LDL (LL-37_LDL) in a cohort without acute disease demonstrated significantly higher levels of LL-37 IgG compared to LL-37_LDL IgG and nLDL IgG. Next, evaluation of LL-37 IgG levels in samples (N = 500) from the AZACS study (Azithromycin in ACS) and population-level associations with clinical characteristics showed that LL-37 IgG levels were s…

open access ↗ · PMID 42304820 · DOI 10.14814/phy2.70914

LL-37 inhibits osteosarcoma progression by suppressing SQLE-mediated cholesterol synthesis via the PTEN/AKT/mTOR pathway — Journal of bone oncology 2026

Osteosarcoma (OS) is an aggressive primary bone malignancy with poor prognosis for metastatic and recurrent cases, highlighting an urgent need for novel therapeutic strategies. The human cathelicidin peptide LL-37 exerts context-dependent anti-tumor effects, yet its functional role in OS remains largely undefined. This study aimed to explore the anti-OS activity and underlying mechanisms of LL-37.MethodsIn vitro experiments were performed using OS cell lines and normal human bone marrow mesenchymal stem cells (hBMSCs) to assess cell viability, clonogenic survival, migration, invasion, cell cycle distribution, cell death, and cholesterol metabolism. Transcriptomic profiling, siRNA-mediated knockdown, plasmid overexpression, and rescue experiments were conducted to validate key signaling pathways. The in vivo therapeutic efficacy of LL-37 was evaluated using a 143B cell xenograft model.Res…

open access ↗ · PMID 42388271 · DOI 10.1016/j.jbo.2026.100779

<em>In Vivo</em> Efficacy of LL-37 and Its Derivative Peptides Against Methicillin-Resistant <em>Staphylococcus aureus</em> in Animal Models: A Systematic Review and Meta-Analysis — Preprints.org 2026

abstract not reproduced — this record is not open-access, so it is linked rather than copied.

publisher record ↗ · DOI 10.20944/preprints202608.1009.v1

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