{{Short description|Group of pore-formng peptides from the skin and intestines of frogs}} {{cs1 config|name-list-style=vanc}} {{this|antimicrobial peptides|the alloy|Manganin}} {{Infobox protein family | Symbol = Magainin | Name = Magainin | image = | width = | caption = | Pfam = | Pfam_clan = | InterPro = | SMART = | PROSITE = | MEROPS = | SCOP = | TCDB = 1.C.16 | OPM family = 211 | OPM protein = 2mag | CAZy = | CDD = }} The '''magainins''' are a class of antimicrobial peptides found in the African clawed frog (''Xenopus laevis'').<ref>{{MeshName|Magainins}}</ref> 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.<ref name=Conlon/>

They were independently discovered at around the same time by the labs of Michael Zasloff at the NIH and Dudley H. Williams at the University of Cambridge.<ref name=Conlon>{{cite journal | vauthors = Conlon JM, Mechkarska M, King JD | title = Host-defense peptides in skin secretions of African clawed frogs (Xenopodinae, Pipidae) | journal = General and Comparative Endocrinology | volume = 176 | issue = 3 | pages = 513–8 | date = May 2012 | pmid = 22036891 | doi = 10.1016/j.ygcen.2011.10.010 }}</ref> They were named by Zasloff, after the Hebrew word for "shield," מגן māgēn (Ashkenazi pronunciation: magain).<ref>Interviewed in 1987, Zasloff explained: "I used it because it came from the skin and it was shielding, in my opinion. What the hell, I hadn't heard a Hebrew name in science before" ({{cite news|author=Susan Okie|title=Frog's Skin Yields Powerful Antibiotic|url=https://www.washingtonpost.com/archive/politics/1987/07/30/frogs-skin-yields-powerful-antibiotic/f4b40db2-4780-46d0-b93d-211d8178767e|newspaper=The Washington Post|date=July 30, 1987}}). In a later interview, his wife, Barbara Zasloff, added: "Tradition would have it that he would have given it a Latin or Greek name. We both felt that he comes from a Hebrew tradition and it would be very appropriate to give it a Hebrew name" ({{cite news|author=Susan Okie|title=A Man and His Frogs|url=https://www.washingtonpost.com/archive/lifestyle/wellness/1988/02/16/a-man-and-his-frogs/8ae0f57d-5c40-4c52-be7f-47105159d5cb|newspaper=The Washington Post|date=February 16, 1988}}).</ref>

Zasloff helped found a company, Magainin Pharmaceuticals (subsequently called Genaera) to develop magainins into drugs.<ref>{{cite news|last1=George|first1=John |title=Biotech Genaera shutting down: Never brought drug to market |url=https://www.bizjournals.com/philadelphia/stories/2009/04/27/daily31.html |work=Philadelphia Business Journal |date=April 29, 2009}}</ref> One candidate was an analog of magainin called pexiganan (MSI-78) that the company developed as a topical agent for infected diabetic foot ulcers; in 1999 the FDA rejected the application because pexiganan was not better than standard treatments.<ref name=Conlon/><ref>{{cite journal | vauthors = Moore A | title = The big and small of drug discovery. Biotech versus pharma: advantages and drawbacks in drug development | journal = EMBO Reports | volume = 4 | issue = 2 | pages = 114–7 | date = February 2003 | pmid = 12612596 | pmc = 1315844 | doi = 10.1038/sj.embor.embor748 }}</ref><ref>{{cite web|title=Pexiganan|url=http://adisinsight.springer.com/drugs/800002904|publisher=AdisInsight|access-date=16 January 2018|language=en}}</ref> Another company, Dipexium Pharmaceuticals, ran further phase III clinical trials for the same use, which failed in 2016.<ref>{{cite news|title=Dipexium's Diabetic Foot Ulcer Candidate Fails Phase III Trials|url=https://www.genengnews.com/gen-news-highlights/dipexiums-diabetic-foot-ulcer-candidate-fails-phase-iii-trials/81253359|work=GEN|date=October 25, 2016}}</ref>

== References == {{reflist}}

{{Pore-forming toxins}}

Category:Antimicrobial peptides