Computational Studies on Syphilis protease inhibitors

Abstract

Syphilis is caused by a bacterium pathogen called Treponema Pollidum. It is the major cause of deaths among pregnant mothers in the third world nations and the incidence of congenital syphilis cannot be overemphasized. However, antibiotics like Tetracycline have been reported to show tremendous antibacterial activity. Therefore, the anti-syphilis activity of some tetracycline molecules were investigated by molecular docking studies. The protein responsible for the bacterial disease was retrieved from protein data bank and docked against tetracycline compounds. Herein, we calculated several DFT reactivity descriptors for the five Tetracycline molecules at the B3LYP/6–311++G(d,p) level of theory in order to analyze its reactivity in vacuum and solvent phases. Theoretical B3LYP/6-31G (d , p) density functional theory has been employed to examine the electronic properties of donorbridge-acceptor molecular system. Oxytetracycline, metacycline and chlorotetracycline showed high inhibition to the receptor with binding affinity of -9.6 kcal/mol. While tetracycline and anhydrotetracycline showed low inhibition with binding affinity of -7.6 kcal/mol.