The magainins are a class of

antimicrobial peptides Antimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Fundamental differences exist between prokaryotic and eukaryotic cells that may represent targets for a ...

found in the

African clawed frog The African clawed frog (''Xenopus laevis'', also known as the xenopus, African clawed toad, African claw-toed frog or the ''platanna'') is a species of African aquatic frog of the family Pipidae. Its name is derived from the three short claws ...

(''Xenopus laevis''). The peptides are cationic, generally lack a stable conformation in water but form amphipathic α-helix in membranes; their mechanism against micro-organisms is unclear but they disrupt the cell membranes of a broad spectrum of bacteria, protozoa, and fungi. They were independently discovered at around the same time by the labs of

Michael Zasloff Michael A. Zasloff (born July 2, 1946) is an American physician, medical researcher, and entrepreneur. Zasloff is primarily known for his work on antimicrobial peptides. Early life Michael Alan Zasloff was born to a Jewish family, the son a de ...

at the NIH and

Dudley H. Williams Dudley Howard Williams (1937–2010) was a British biochemist known for utilizing nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry in the study of molecular structure, especially the antibiotic vancomycin. Biography Dudley H ...

at the University of Cambridge. They were named by Zasloff, after the

Hebrew Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...

word for "shield," מגן māgēn (

Ashkenazi Ashkenazi Jews ( ; he, יְהוּדֵי אַשְׁכְּנַז, translit=Yehudei Ashkenaz, ; yi, אַשכּנזישע ייִדן, Ashkenazishe Yidn), also known as Ashkenazic Jews or ''Ashkenazim'',, Ashkenazi Hebrew pronunciation: , singu ...

pronunciation: magain). Zasloff helped found a company, Magainin Pharmaceuticals (subsequently called Genaera) to develop magainins into drugs. One candidate was an analog of magainin called pexiganan (MSI-78) that the company developed as a topical agent for infected

diabetic foot ulcer Diabetic foot ulcer is a major complication of diabetes mellitus, and probably the major component of the diabetic foot. Wound healing is an innate mechanism of action that works reliably most of the time. A key feature of wound healing is stepw ...

s; in 1999 the FDA rejected the application because pexiganan was not better than standard treatments. Another company, Dipexium Pharmaceuticals, ran further phase III clinical trials for the same use, which failed in 2016.

References

{{Pore-forming toxins Antimicrobial peptides