Cathelicidin LL-37
Brief Introduction:
LL-37 is the only cathelicidin antimicrobial peptide found in the human body. It is composed of 37 amino acids at the N-terminus of the cathelicidin protein, and the starting amino acids are L-L, hence the name LL-37.
LL-37 is the main protein in neutrophils and is widely present in neutrophils, bone marrow, cervical and vaginal squamous epithelial cells.
The LL-37 precursor consists of a signal peptide, a cathelin conserved region and 37 amino acid residues, when the cell is activated, it is cleaved by serine protease 3 and other proteolytic enzymes to produce biologically active LL-37, which has antibacterial, antifungal and antiviral functions, as well as chemotaxis and immune stimulation/regulation.
Sequence:
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
Mechanism of Action:
LL-37 may interact with the phospholipid bilayer through the N-terminus of the polymer, disrupt the arrangement of phospholipid molecules in the cell membrane, change the membrane permeability, affect the structure and function of the cell membrane, cause a large amount of intracellular substances to extravasate, and cause cell death; it may also cause cell death by inhibiting the synthesis of intracellular nucleic acids and proteins, enzyme activity and cell wall synthesis.
Functions of Antimicrobial Peptide LL-37 (human):
✹ Antimicrobial:
As an important member of the natural immune system, LL-37 has strong antimicrobial activity both in vivo and in vitro, including Gram-positive bacteria (such as Staphylococcus aureus, Streptococcus, etc.), Gram-negative bacteria (such as Salmonella, Escherichia coli, etc.), fungi and viruses. Moreover, LL-37 also has a certain selective killing effect on some fungi, viruses, tumor cells and protozoa.
✹ Regulate the Release of Immune and Inflammatory Mediators:
LL-37 can cause immune cell differentiation and chemotaxis, induce cell differentiation, cytokine release, neutralize endotoxins and anti-tumor, etc., and enhance the body's ability to resist harmful microorganisms.
Advantages:
Compared with traditional antibiotics, Antimicrobial Peptide LL-37 human can kill pathogens, is not easy to produce drug resistance, and is not easy to produce immune rejection reactions. It is an important effector molecule of the natural immune system.
Application Prospects of LL-37:
✹ New Drugs:
Low expression of TLR2 and LL-37 and low level of serum LL-37 in children with atopic dermatitis (AD) suggest that AD has problems such as innate immunity and skin barrier function defects. Vitamin D may activate vitamin D receptors and promote LL-37 expression through the TLR2 pathway, thereby protecting AD. Perhaps in the future, LL-37-related drugs can be designed to assist vitamin D in combating atopic dermatitis.
Neonatal sepsis is mainly caused by infection. With the emergence of drug-resistant bacteria, antibiotic selection has become increasingly difficult, so it is particularly important to improve one's own resistance. Studies have shown that vitamin D can increase the expression of the body's antimicrobial peptide LL-37, thereby improving the body's ability to defend against infection and providing strong protection for antibiotic treatment. This will provide ideas for designing drugs that replace antibiotics.
✹ Animal Feed Additives:
LL-37 has a broad antibacterial spectrum and high antibacterial activity, bacteria are not easy to develop drug resistance, it can also neutralize endotoxins and can be regarded as a new alternative to antibiotics. Therefore, choosing a suitable expression template to express LL-37 analogs will promote the production of animal feed additives with high antibacterial efficiency and high nutrition, making it have certain economic benefits.
✹ Preservatives:
LL-37 and CP1 are produced on a large scale through genetic engineering, they have strong antibacterial activity, small relative molecular mass, high antibacterial activity when heated at 121℃ for 30 minutes, good water solubility, safe and non-toxic, and not easy to develop drug resistance. Adding an appropriate amount of antimicrobial peptides to milk has a certain preservation effect on storage.
Specifications of our LL-37 (human):
| Test Items | Specifications |
| Appearance | White powder |
| Purity (HPLC) | Not less than 98.0% |
| Acetate Content (HPLC) | Less than 15.0% |
| Peptide Content (N%) | Not less than 75.0% |
| Water Content (Karl Fischer) | Not more than 10.0% |
| MS (ESI) | Conforms |
| Mass Balance | 95.0% ~ 105.0% |
Packaging:
1g/Bottle, 2g/Bottle, 3g/Bottle, 5g/Bottle or according to the specific requirements from customers.
Storage Conditions:
Stored in a cool dry place away from sunlight and moisture.
Shelf Life:
24 months from the date of manufacturing when stored under the above mentioned conditions.
