Simulation Study Of The Antibiotic Mechanism Of Antimicrobial Peptide Phylloseptin-1,-2,-3and The Agonistic Mechanism Of A Superagonistic Anti-cytokine Antibody

With the development of computer, computer technology is widely used in many fields such as computational biology, computational chemistry and drug molecules design. It researchs the relationship between structure and function at molecular level and not limited by the sample preparation and test technical. So, it can provide more reference and experiment guidance for scientists. In this paper computer technology is used to study the antibacterial mechanism of antimicrobial peptides Phylloseptin-1,-2,-3and superagonistic action of superagonistic antibody2Z2to the biological activity of human interleukin21(HIL-21).1. Antimicrobial peptides are considered to be the best choice to replace traditional antibiotics because of its wide varieties, broad-spectrum bactericidal activity and strong drug-resistant. Antimicrobial peptides Phylloseptin-1,-2,-3are isolated from skin secretion of South American amphibian Phyllomedusa hypochondrialis, which with74%sequence homology and shownd a broad-spectrum bactericidal activity.To study these possible antibacterical mechanism, several molecular dynamics simulations systems were performed in which the number of the peptide was varied. The simulation results showed that Phylloseptin-1,-2,-3have the similar dynamics antibacterial behavior. Interaction with the POPC, one peptide can not cause perceptible distortion of the overall bilayer structure, but high concentration of the peptide which cause peptides aggregation can lead a spontaneous defect on the membrane surface, change the permeability of the membrane and then kill the bacteria.2. There are several superagonistic antibody have been reported in recent years. They recognize specific cytokine molecules and are able to act in an agonistic or even superagonistic way by binding to the native molecule. However, the superagonistic mechanism of these antibodies is unclear. In order to study the superagonistic action of the superagonistic antibody2Z2to the biological activity of human interleukin21(HIL-21), the complex of HIL-21and2Z2is predicted by molecular docking. The results showed that the epitope in HIL-21of the superagonistic antibody2Z2and unsuperagonistic antibody3B3is different, the epitope of2Z2is mainly in the B Helix and CD Loop. By the amino acids (in epitope) mutations experiment to guide the research which is performed to study the superagonistic mechanism of...