LL-37 fragment (17-29)

Product Name: LL-37 fragment (17-29)

Sequence One Letter Code: FKRIVQRIKDFLR

Sequence Three Letter Code: H-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-OH

Cas No: 717919-68-1

Chemical Formula:C80H135N25O17

Molecular Weight: 1719.2

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Infection Disease Research

SMILES: CC[C@H](C)[C@@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC1=CC=CC=C1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCN=C(N)N)C(=O)O)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@H](C(C)C)NC(=O)[C@H]([C@@H](C)CC)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC2=CC=CC=C2)N.C(=O)(C(F)(F)F)O

IUPAC: (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-5-amino-2-[[(2S)-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-amino-3-phenylpropanoyl]amino]hexanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-3-methylpentanoyl]amino]-3-methylbutanoyl]amino]-5-oxopentanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-3-methylpentanoyl]amino]hexanoyl]amino]-3-carboxypropanoyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]-5-(diaminomethylideneamino)pentanoic acid;2,2,2-trifluoroacetic acid

INCHIKEY: AHXZTIFPEFVUCT-VNBFMRIASA-N

INCHI:

InChI=1S/C80H135N25O17.C2HF3O2/c1-9-46(7)63(75(119)97-52(29-18-20-36-82)67(111)102-59(43-61(107)108)73(117)101-58(42-49-26-15-12-16-27-49)72(116)100-57(40-44(3)4)71(115)99-56(77(121)122)32-23-39-93-80(89)90)104-69(113)54(31-22-38-92-79(87)88)96-68(112)55(33-34-60(84)106)98-74(118)62(45(5)6)103-76(120)64(47(8)10-2)105-70(114)53(30-21-37-91-78(85)86)95-66(110)51(28-17-19-35-81)94-65(109)50(83)41-48-24-13-11-14-25-48;3-2(4,5)1(6)7/h11-16,24-27,44-47,50-59,62-64H,9-10,17-23,28-43,81-83H2,1-8H3,(H2,84,106)(H,94,109)(H,95,110)(H,96,112)(H,97,119)(H,98,118)(H,99,115)(H,100,116)(H,101,117)(H,102,111)(H,103,120)(H,104,113)(H,105,114)(H,107,108)(H,121,122)(H4,85,86,91)(H4,87,88,92)(H4,89,90,93);(H,6,7)/t46-,47-,50-,51-,52-,53-,54-,55-,56-,57-,58-,59-,62-,63-,64-;/m0./s1

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: LL-37 Fragment (17–29) is a bioactive peptide derived from the C-terminal region of the human cathelicidin antimicrobial peptide LL-37. This segment retains strong antimicrobial properties and contributes to innate immune defense by disrupting microbial membranes and inhibiting bacterial growth. In addition to its antibacterial activity, the peptide has been shown to influence host immune responses, including modulation of inflammatory signaling pathways and immune cell activation. LL-37 fragments have also been studied for their roles in wound healing, tissue repair, and host–pathogen interactions. Because it preserves key functional characteristics of the parent peptide while offering a shorter and more experimentally manageable sequence, LL-37 (17–29) is widely used in research focused on antimicrobial peptide mechanisms, immune modulation, and infection biology.

Current Research: Antimicrobial peptides (AMPs) are an essential component of the innate immune system, providing rapid protection against invading microorganisms. Among the best-studied human AMPs is LL-37, the only member of the human cathelicidin family, which plays a central role in antimicrobial defense, immune regulation, and tissue repair. Researchers frequently investigate smaller fragments of LL-37 to better understand the structural features responsible for its biological activity. LL-37 Fragment (17–29) is a synthetic peptide derived from the C-terminal region of the LL-37 sequence, encompassing amino acids 17 through 29. Despite its shorter length, this fragment retains key functional characteristics of the parent peptide, including antimicrobial activity and the ability to influence immune responses. Because it preserves essential bioactive features while offering a more manageable sequence for experimental work, LL-37 (17–29) has become a valuable research tool in studies of innate immunity, antimicrobial mechanisms, and host–pathogen interactions. LL-37 and the Human Cathelicidin System LL-37 originates from the precursor protein human cationic antimicrobial protein 18 (hCAP18). Upon activation by proteolytic cleavage, hCAP18 releases the active peptide LL-37, which contains 37 amino acids and begins with two leucine residues—hence the name “LL-37.” LL-37 is expressed in a wide range of human cells and tissues, including: Neutrophils Epithelial cells Macrophages Skin and mucosal tissues Its broad distribution highlights its importance in frontline defense against microbial pathogens. LL-37 participates not only in direct antimicrobial activity but also in immune signaling, inflammation regulation, and tissue repair processes. Antimicrobial Mechanisms of LL-37 Fragments The antimicrobial activity of LL-37 is primarily associated with its cationic and amphipathic structure, which allows the peptide to interact with negatively charged microbial membranes. This interaction can disrupt membrane integrity and compromise bacterial viability. The 17–29 region of LL-37 contains residues that contribute to these membrane-active properties. Studies have shown that fragments derived from this region can retain significant antimicrobial activity against a variety of microorganisms. The mechanisms involved often include: Membrane disruption, leading to leakage of cellular contents Destabilization of bacterial membranes, affecting membrane potential Inhibition of microbial growth, limiting pathogen proliferation Because bacterial membranes differ significantly from mammalian cell membranes in their lipid composition and charge, antimicrobial peptides can preferentially target microbial cells. Immunomodulatory Functions Beyond its direct antimicrobial activity, LL-37 is known for its immunomodulatory effects, which help coordinate the body’s response to infection. Fragments such as LL-37 (17–29) have been studied for their ability to influence immune signaling pathways and cellular responses. Research suggests that LL-37-derived peptides may: Modulate inflammatory signaling pathways Influence cytokine production Affect immune cell activation and recruitment These regulatory roles highlight the importance of antimicrobial peptides not only as microbial inhibitors but also as immune signaling molecules that help orchestrate host defense mechanisms. Roles in Wound Healing and Tissue Repair LL-37 and its fragments have also been investigated for their involvement in wound healing and tissue regeneration. During tissue injury, antimicrobial peptides contribute to maintaining a protective environment while promoting repair processes. Studies suggest that LL-37-derived peptides may support wound healing through several mechanisms, including: Promoting cell migration and proliferation Modulating inflammatory responses Supporting angiogenesis and tissue remodeling These properties make LL-37 fragments of interest in research exploring the intersection of immune defense and tissue repair. Advantages of the LL-37 (17–29) Fragment The full LL-37 peptide is relatively long and can present experimental challenges related to synthesis, stability, or structural complexity. Shorter fragments such as LL-37 (17–29) offer several practical advantages for research applications. These advantages include: Reduced peptide length, simplifying synthesis and experimental handling Retention of key functional motifs, preserving biological activity Improved suitability for mechanistic studies, allowing targeted investigation of structure–function relationships Because of these properties, the fragment serves as a convenient model for examining the functional domains responsible for LL-37 activity. Applications in Antimicrobial and Immunology Research LL-37 (17–29) is widely used in laboratory studies focused on understanding antimicrobial peptide biology and host defense mechanisms. Typical research applications include: Antimicrobial mechanism studies Researchers use the peptide to analyze how cationic peptides interact with microbial membranes and inhibit pathogen growth. Host–pathogen interaction research The peptide helps investigate how antimicrobial peptides influence interactions between immune cells and invading microbes. Immune signaling studies LL-37 fragments can be used to explore pathways involved in inflammatory responses and immune cell activation. Structure–function analysis By examining smaller peptide fragments, scientists can determine which regions of LL-37 are responsible for specific biological activities. Supporting Research on Innate Immune Defense Antimicrobial peptides are increasingly recognized as multifunctional molecules that link direct antimicrobial defense with immune regulation and tissue repair. Understanding how these peptides function is essential for advancing research in infection biology and immunology. The LL-37 Fragment (17–29) provides a practical experimental model that retains key biological activities of the parent LL-37 peptide while offering a shorter and more experimentally manageable sequence. Through its use in antimicrobial assays, immune signaling studies, and host–pathogen interaction research, this peptide contributes to a deeper understanding of how innate immune mechanisms protect the body against microbial threats.