Talking about antimicrobial peptide


Antibiosis peptide is also known as antimicrobial peptide and peptide antibiotics, wide spread in vivo animals, and is a part of natural immune defense system. This kind of bioactive peptides have characteristics of strongly alkaline, thermal stability, and wide antimicrobial spectrum, and can act on fungus, virus and tumor cells. 

1. Structure and characteristics of antimicrobial peptide

Nature antimicrobial peptide is alkalic low molecular polypeptide that generally consisted of more than 30 amino acid residues, its water-solubility is good, and its molecular weight is about 4kDa. Most of antimicrobial peptide have thermal stability, and can maintain its activity by heating 10~15min at 100℃.

2. Antibacterial mechanism and characteristics of antimicrobial peptide

(1) Antibacterial mechanism of antimicrobial peptide

At present, it is thought that antimicrobial peptide act on cell membrane, form trans-membrane ion channels on membrane, destroy integrity of membrane, cause leakage of cellular contents, thus to kill cells, however mechanisms of diverse kinds of antimicrobial peptide are possibly different.

(2) Characteristics of antimicrobial peptide

a. Effectiveness of site of action

Antimicrobial peptide act on bacterial cellular membrane, that cause permeability of membrane to increase, thus to penetrate and kill bacteria. Bacteria has to change its membrane structure, in other words it has to change tremendous parts of gene to defense attack of antimicrobial peptide, which is almost impossible. Therefore, antimicrobial peptide reduce potential of drug-resistant greatly.

b. Selection of object of action

Antimicrobial peptide can only act on prokaryotic cells and lesion Eukaryotic cells, and it doesn’t work on normal Eukaryotic Cell.

3. Biological characteristics of antimicrobial peptide

(1) Broad spectrum antimicrobial 

(2) Work with speed, safety and no residues

(3) Stimulate immune reaction

(4) Jointly work with other antibiosis substances

(5) Have strong resistance to environment, and is suitable for being additive