Have anti-biofilm and antifungal activities against C. albicans and C. glabrata (Wang K et al. 2014). A mast cell lytic peptide, chemotaxis for polymorphonucleated leukocytes (PMNL). Not toxic to rat erythrocytes. Helix in SDS or TFE. Replacement of residue 7, 8, or 9 by a proline led to reduced helicity as well as antitumor activity (Wang et al. 2008) Peptides 29: 963-968. Animal model:mouse: A single atom change (CO-NH2 to CS-NH2) of MPI improved peptide stability to serum proteases and better inhibited sarcoma xenograft tumor (S180) growth from 18 (WT) to 38% (mutant) using a Kunming mouse model (Zhang W et al. 2010 Peptides 31:1832-8). Updated 9/6/12; 3/2014 GW. Polybia-MPI has Antibacterial activity. Polybia-MPI was found in venom, social wasp, Polybia paulista.
Souza BM, Mendes MA, Santos LD, et al. Structural and functional characterization of two novel peptide toxins isolated from the venom of the social wasp Polybia paulista. Peptides. 2005;26(11):2157-64.