Structural Analysis of Saxitoxin and its Analogs: a Computational Study

Saxitoxin (STX) is a potent neurotoxin produced by certain species of seaweed (dinoflagellates) and cyanobacteria. Saxitoxin has more than 50 analogs, but in this work, we studied only saxitoxin and its analogs GTX5, GTX2/3, and C1/2, which are mollusk paralyzing toxins (PSTs). Because it is highly lethal and its mechanism of action has not yet been fully elucidated, it can be used as a biological weapon. This project addresses an in silico study on the interactions of STX and its analogs selected with potential targets in order to understand its mechanism of action. Initially, the 3D structure selected in the PDB database was the Saxiphilin protein, identified by the PDB code ID 8D6M. The results obtained in this project through molecular docking performed by AMDockVina show us that some residues are present in some interactions of Saxifilin with STX and its analogs, and the residues that appear repeatedly are aspartic acid, glutamic acid, and glycine. Furthermore, we performed a search against the BLAST database for human sequences homologous to Saxiphilin. The sequence that presented the greatest identity of 41.22% and coverage of 84% was the Lactoferrin sequence. The next will step will be to perform new docking simulations with STX and its analogs using the 3D structre of Lactoferrin.