Metchnikowin is a 26-residue antimicrobial peptide of the fruit fly ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Ch ...

'' that displays both antibacterial and antifungal properties. This peptide is expressed strongly in the ''Drosophila'' fat body (an organ similar to the human liver), but is also expressed at surface epithelia in the trachea and gut. This is regulated by the NF-κB signalling pathways Toll and Imd. Metchnikowin is named after Russian immunologist

Élie Metchnikoff Ilya Ilyich Mechnikov (russian: Илья Ильич Мечников; – 15 July 1916), also spelled Élie Metchnikoff, was a Russian zoologist best known for his pioneering research in immunology. Belkin, a Russian science historian, explains ...

, one of the founders of modern immunology.

Structure and function

Metchnikowin has microbicidal activity against the gram-negative bacterium ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'' and filamentous fungus '' Neurospora crassa'' at nanomolar concentrations. It is also one of the most abundant defence peptides in ''D. melanogaster'' following infection by the entomopathogenic fungus ''

Beauveria bassiana ''Beauveria bassiana'' is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is used as a biological ...

''. Proline-rich peptides such as metchnikowin can bind to microbe

ribosome Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to ...

s, preventing

protein translation In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. The entire process is ...

References

{{Reflist Drosophila Insect immunity Antimicrobial peptides