1.C.68 The Channel-forming Oxyopinin Peptide (Oxyopinin) Family

Oxyopinins are cationic amphipathic peptides with antimicrobial, hemolytic, and insecticidal activities. They are from the venome of the wolf spider, Oxyopes kitabensis (Corzo et al., 2002). Corzo et al. report that they are similar in sequence to the ant venome insecticidal peptide, ponericin-L2 (P82422), which exhibits antimicrobial activities but has not been shown to exhibit pore-forming activity, and the frog antimicrobial peptide dermaseptin (TC #1.C.52.1.1). If so, they are very distantly related and were not retrieved in a BLAST search.

Oxyopinins are probably α-helical with a single TMS. They disrupt biological and artificial membranes and open oligomeric, non-selective, ion pores (Corzo et al., 2002). They undoubtedly form oligomeric channels.

The transport reaction catalyzed by oxyopinins is:

small molecules (in) small molecules (out)