Peptable

Comparison

LL-37 vs Melanotan I

Function

While LL-37 acts as a broad-spectrum antimicrobial and immunomodulatory peptide involved in host defense and wound repair, but can also promote inflammation and cancer cell proliferation in some contexts5215, Melanotan I is approved in some regions for prevention of phototoxicity in erythropoietic protoporphyria and is studied as a skin-darkening, photoprotective peptide3444.

Mechanism

While LL-37 works as a cationic amphipathic 37-amino-acid cathelicidin peptide generated from hCAP18 that disrupts microbial membranes and modulates innate immunity, including chemotaxis, cytokine induction, and NET formation521586, Melanotan I is a linear 13-amino-acid analog of α-MSH (afamelanotide) that selectively activates MC1R on melanocytes, increasing eumelanin synthesis and providing photoprotection3444.

Receptor

LL-37

Functions as a ligand for CXCR2 on neutrophils and other myeloid cells; LL-37 signaling has also been linked to FPR2 and P2X7 in various cell types515

Melanotan I

Melanocortin-1 receptor (MC1R) 344481

Organism or Origin

LL-37

Human cathelicidin antimicrobial peptide generated from the CAP-18 precursor5286

Melanotan I

Synthetic analog of human α-MSH derived from POMC34448190

Gene

LL-37

CAMP

Melanotan I

POMC

Summary

LL-37 and Melanotan I are noticeably different, with limited direct overlap in their usual biological context. Their typical research and application settings separate fairly clearly: LL-37 is more often discussed in the realm of Immunology and inflammation and Gastroenterology, whereas Melanotan I is more often associated with the realm of Dermatology and aesthetics. They also influence different molecular systems, with LL-37 tracking more closely to GPCR receptor while Melanotan I centers more on Melanocortin receptor. LL-37 has a more natural endogenous origin, while Melanotan I is closer to synthetic analog background with LL-37 in Preclinical development and Melanotan I approved for Research use only. Melanotan I incorporates d-amino acid substitution features that are not part of LL-37, while their sequence patterns also diverge, with LL-37 showing cationic amphipathic and alpha-helical domain features and Melanotan I showing protein-mimetic sequence features.

Related articles

No related articles are linked to these peptides yet.

Sources

52Cathelicidin LL-37: A new important molecule in the ... - PMC - NIH, https://pmc.ncbi.nlm.nih.gov/articles/PMC7388365/
86Cathelicidin antimicrobial peptide - Wikipedia, https://en.wikipedia.org/wiki/Cathelicidin_antimicrobial_peptide
34Melanotan I (Afamelanotide): Research Profile - PeptideJournal, https://www.peptidejournal.org/peptides/melanotan-i-research-profile
44Melanotan I: properties, applications and references, https://www.benchchem.com/zh/product/b1666627
81Proopiomelanocortin (POMC), the ACTH/melanocortin precursor, is ..., https://pmc.ncbi.nlm.nih.gov/articles/PMC2253185/
90alpha-Melanocyte stimulating hormone: production and degradation, https://pmc.ncbi.nlm.nih.gov/articles/PMC3936413/