Computational Modelling of Cruzioseptin-4 Extracted From the Frog Cruziohyla Calcarifer and Pictuseptin-1 Extracted From the Frog Boana Picturatus

Abstract

Abstract A computational study of the peptides Cruzioseptin-4 and Pictuseptin-1, identified in Cruziohyla calcarifer and Boana picturatus respectively, has been carried out. The studies on cruzioseptin-4 show that it is a cationic peptide with a chain of 23 amino acids that possess 52.17% of hydrophobic amino acids and a charge at pH 7 of + 1.2. Similarly, pictuseptin-1 is a 22 amino acids peptide with a charge at pH 7 of + 3 and 45.45% of hydrophobic amino acids. Furthermore, the predominant secondary structure for both peptides is alpha-helical. Finally, the molecular docking study indicates that the viable mechanism of action for both peptides is through a targeted attack on the cell membrane of pathogens via electrostatic interactions with different membrane components, leading to cell lysis. The physicochemical properties were predicted using Pep Calc and Biosyn; secondary structures using Jpred 4 and Predict Protein; while molecular docking was performed using Autodock VINA. Geometry optimization of the peptides was done using the ONIOM hybrid method with the HF/6-31G basis set implemented in the Gaussian09 program.