1.C.62 The Pseudopleuronectes americanus (flounder) Pleurocidin (Pleurocidin) Family

Pleurocidin is an antibacterial peptide that forms ion channels in planar lipid bilayers. Its activity depends on the presence of small amounts of anionic phospholipids such as phosphatidyl serine. The channel, probably a toroidal pore, is not voltage dependent and displays only one unitary conductance. It is active against Gram-negative and Gram-positive bacteria and plays a role in host defense by forming pores that induce cell lysis. Pleurocidin is 25 aas long and is derived from a 60 or 68 aa precursor prepropolypeptide. At least three such precursors of similar but different amino acid sequence have been sequenced from P. americanus.

The Pleurocidin family is related to the Dermaseptin family of amphibian peptide (TC #1.C.52) toxins as well as the insect ceratotoxins (Bessin et al., 2004) and the insect cecropins (TC #1.C.17).

The transport reaction catalyzed by pleurocidin is:

small moleculesin small moleculesout.

This family belongs to the Cecropin Superfamily.



Bessin, Y., N. Saint, L. Marri, D. Marchini, and G. Molle. (2004). Antibacterial activity and pore-forming properties of ceratotoxins: a mechanism of action based on the barrel stave model. Biochim. Biophys. Acta 1667: 148-156.

Cole, A.M., P. Weis, and G. Diamond. (1997). Isolation and characterization of pleurocidin, an antimicrobial peptide in the skin secretions of winter flounder. J. Biol. Chem. 272: 12008-12013.

Perrin, B.S., Jr, R. Fu, M.L. Cotten, and R.W. Pastor. (2016). Simulations of Membrane-Disrupting Peptides II: AMP Piscidin 1 Favors Surface Defects over Pores. Biophys. J. 111: 1258-1266.

Saint, N., H. Cadiou, Y. Bessin, and G. Molle. (2002). Antibacterial peptide pleurocidin forms ion channels in planar lipid bilayers. Biochim. Biophys. Acta 1564: 359-364.

Tamang, D.G. and M.H. Saier, Jr. (2006). The cecropin superfamily of toxic peptides. J. Mol. Microbiol. Biotechnol. 11: 94-103.


TC#NameOrganismal TypeExample
1.C.62.1.1PleurocidinFishPleurocidin precursor of Pseudopleuronectes americanus

Animicrobial peptide, Piscidin 1, of 68 aas.  Forms pore, but preferentially forms disrupting surface structures (Perrin et al. 2016).

Piscidin 1 of Oreochromis niloticus (Nile tilapia) (Tilapia nilotica)


Piscidin 2 of 77 aas

Picidin 2 of Oreochromis niloticus (Nile tilapia) (Tilapia nilotica)


Piscidin 3 of 76 aas, TP3.

Piscidin 3, TP3 of Oreochromis niloticus (Nile tilapia) (Tilapia nilotica)