Host defence peptide
A Host defence peptide (or antimicrobial peptide) is one of a part of the innate immune response. They are found among all classes of life.
They act against invading microorganisms. The peptides kill Gram negative and Gram positive bacteria. This includes strains which are resistant to conventional antibiotics. The peptides also work against mycobacteria (including Mycobacterium tuberculosis), enveloped viruses, fungi and even transformed or cancerous cells.[1]
These peptides are excellent candidates for medical use. They complement conventional antibiotic therapy. They have a broad range of activity, and are bactericidal as opposed to bacteriostatic.[1] They need only a short contact time to kill bacteria.
There are big differences between prokaryotic and eukaryotic cells as targets for antimicrobial peptides. These peptides are potent, broad spectrum antibiotics. Unlike most antibiotics it seems that antimicrobial peptides may also improve immunity by working as immunomodulators (beefing up the immune system).
Host Defence Peptide Media
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Antimicrobial peptides from animals, plants and fungi organised by their secondary structure content. Circle size indicates overall molecular weight of each peptide.
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The modes of action by Antimicrobial peptides
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Schematic representation of the AMPs mechanisms of action when disrupting membranes.
Mechanim of Selectivity of Antimicrobial Peptides
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Fruit flies infected by GFP-producing bacteria. Red-eyed flies lacking antimicrobial peptide genes are susceptible to infection, while white-eyed flies have a wild-type immune response.