A new type of antimicrobial peptide

Abstract

The invention provides a novel antimicrobial peptide, and belongs to the field of the application of peptide antibiotics. The antimicrobial peptide adopts alternating arrangement of hydrophilic and hydrophobic amino acids, and appears the random coil structure in water solution, forms regular helical structure in the phospholipid membrane environment, has a stable structure, and comprises the amino acid sequence with the following structural formula: (a) (A1A2B1B2)nA3, (b) G(A1A2B1B2)n A3, or (c) G(A1A2B1B2)n, wherein A1, A2, and A3 are respectively selected from Leu, Val, Ile, Nle, , Phe, or Ala; B1 and B2 are respectively selected from Arg, Lys, Orn, His, 2,4-Dab or 2,3-Dap; G is Gly; n is elected form 3-4. The antimicrobial peptide has very high antineoplastic activity and antibacterial activity, can inhibit the growth of more than 50% of tumours in a naked mouse antineoplastic experiment, and can save the lives of more than 80% of mice in a Kunming mouse infection (ESBL bacterial infection) experiment.

Description

technical field [0001] The invention relates to an antibacterial peptide, in particular to an antibacterial peptide with a helical structure, belonging to the application field of peptide antibiotics. Background technique [0002] Antibiotic drugs such as penicillins, cephalosporins, aminoglycosides, macrolides, etc., mainly bind to intracellular target proteins and destroy a certain physiological process in bacteria to inhibit the growth of bacteria. The use of methionine will cause problems such as drug residues and bacterial resistance, so it is urgent to find a green, pollution-free and non-bacterial resistance alternative. The antimicrobial peptides discovered in recent years are different from antibiotics. Antimicrobial peptides mainly act on the cell membrane of invading microorganisms, leading to cell lysis and eventually death. A small peptide substance with broad-spectrum antibacterial activity, which is an important part of the biological non-specific defense sys...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many types and quantities of antimicrobial peptides, and their structures are complex and changeable. However, genetic engineering methods are used blindly to express antimicrobial peptides without a comprehensive discussion on the structure, function, and in vivo and in vitro activities of antimicrobial peptides, resulting in most of the expressed antimicrobial peptides. The activity is not high, or it has hemolytic activity and cytotoxicity. So far, there have been many methods to study the relationship between the structure and function of antimicrobial peptides. The antimicrobial peptides are generally natural antimicrobial peptides. Although natural antimicrobial peptides are obtained through many channels , but there are deficiencies such as low yield and unclear mechanism of non-specific immune response of the body; many scholars chemically synthesized some antibacterial peptides with self-assembly ability, and explored their antibacterial activity

However, the main components forming nanoparticles are lipopeptides or cyclic peptides. The lipopeptides have a long hydrophobic chain, high synthesis cost and strong toxic effect on the body. In addition, its structure is relatively complicated, which is not conducive to grasping its structure-activity relationship.

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