1.C.51 The Pilosulin (Pilosulin) Family

The major allergen Myr PI precursor (MyrPI) is a secreted protein that binds IgE. It is derived from the venom gland of the jumper ant, Myremecia pilosula. A 56 aa peptide derived from the C-terminus of the 112 aa protein is a catonic, amphipathic peptide with lysyl and arginyl residues found at regular intervals (3-4 residues) in an oligomeric hydrophobic peptide.

Melittin (1.C.18) and pilosulin both appear to exhibit degenerate repeat units. In melittin, the repeated sequence is: (33) EPAP/EAEA/EADA/EADP. In pilosulin, it is: (33) ESEAVG/FADAFG/EADAVG/EADP. These two proteins give a comparison score of 9.5 SD. Thus we believe that they contain repeat units that may have derived from a common origin.

This cytotoxic peptide forms oligomeric ion-conducting channels catalyzing:

Ions (in) ions (out)