Comparison

LL-37 vs SS-31

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, SS-31 improves mitochondrial bioenergetics, reduces oxidative stress, and shows protective effects in models of ischemia-reperfusion, neurodegeneration, and other mitochondrial disorders4637137.

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, SS-31 is a mitochondria-targeted tetrapeptide, d-Arg-dimethylTyr-Lys-Phe-NH2, that selectively binds cardiolipin in the inner mitochondrial membrane, stabilizing cristae structure, improving electron transport, and reducing ROS production4637137143.

Length and Sequence

LL-37 is 37 amino acids long, whereas SS-31 is shorter as it has a length of 4 amino acids. LL-37 is made up of a sequence of Leucine, Leucine, Glycine, Aspartic acid, Phenylalanine, Phenylalanine, Arginine, Lysine, Serine, Lysine, Glutamic acid, Lysine, Isoleucine, Glycine, Lysine, Glutamic acid, Phenylalanine, Lysine, Arginine, Isoleucine, Valine, Glutamine, Arginine, Isoleucine, Lysine, Aspartic acid, Phenylalanine, Leucine, Arginine, Asparagine, Leucine, Valine, Proline, Arginine, Threonine, Glutamic acid, Serine. SS-31 is made up of a sequence of Arginine, dimethylTyr, Lysine, Phenylalanine.

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

SS-31

Cardiolipin-rich inner mitochondrial membrane; interacts with cardiolipin and associated mitochondrial proteins rather than a classical cell-surface receptor46137143

Organism or Origin

LL-37

Human cathelicidin antimicrobial peptide generated from the CAP-18 precursor5286

SS-31

Fully synthetic Szeto–Schiller tetrapeptide; not encoded in the genome4637

Gene

LL-37

CAMP

SS-31

Not assigned in the current dataset.

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
46Discovery of novel SS-31 (d-Arg-dimethylTyr-Lys-Phe-NH2 ... - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC11409442/
56Discovery of novel SS-31 (d-Arg-dimethylTyr-Lys-Phe-NH2 ..., https://pubs.rsc.org/en/content/articlelanding/2024/ra/d4ra05517a
137Mitochondrial protein interaction landscape of SS-31 | PNAS, https://www.pnas.org/doi/10.1073/pnas.2002250117
143SS-31 Peptide: Mitochondrial Repair for Energy and Longevity, https://revolutionhealth.org/blogs/news/peptide-therapy-ss-31