M-poneritoxin-Dq4b: this synthetic peptide has antimicrobial activity against Gram-positive bacteria B.amyloliquefacies S499 (MIC=0.1 mM), L.monocytogenes 2231 and S.aureus ATCC 29213, against Gram-negative bacteria P.putida BTP1, P.aeruginosa PaO1 and E.coli ATCC 10536, and against the fungi S.cerevisiae, R.mucilaginosa and C.cucumerinum. Not active against the fungi F.oxysporum and B.cinerea. Expressed by the venom gland. Occurs in 3 forms, M-PONTX-Dq4b has an amidated Ala-28, U1-PONTX-Dq4d has an amidated Ala-28 and an oxidized Met-20, U1-PONTX-Dq4c has no modifications at either Met-20 or Ala-28. M-PONTX-Dq4b. U1-PONTX-Dq4c. U1-PONTX-Dq4d.