Molecular Dynamics Simulations of Arthropods Antimicrobial Peptides Css54 and La47 with POPC and POPG membranes

The search for new and effective antimicrobial agents has led to the identification of Antimicrobial Peptides (AMPs). Css54 and La47 are AMPs from Centruroides suffusus suffusus (scorpion) and Lashesana sp. (spider), respectively. These peptides and their variants showed different antibacterial and hemolytic activities.

To know how the AMPs interact with membrane models of bacteria (POPG) and erythrocyte (POPC), 200 ns molecular dynamics simulations were carried out using Gromacs 5.1.4. Some parameters like area per lipid, secondary structure, hydrogen bonds, electrostatic interactions and binding energies were calculated.

Preliminary results indicated that these AMPs interacted mainly through its N terminus with the help of charge and hydrophobic residues. The peptides showed more stable interaction in POPG than in POPC. Linking qualitatively the calculated parameters with experimental information, we found that the differences in hemolytic activities between Css54/variants and La47/variants were associated mainly to the percentage of hydrophobic residues (greater in Css54/variants).