Molecular docking and inhibition profiles of some antibiotics on lactoperoxidase enzyme purified from bovine milk

Abstract

Antibiotics are generally used for human and veterinary applications to preserve and to control microbial diseases. Milk has a biologically significant enzyme known as lactoperoxidase (LPO) that is a member of peroxidase family. In metabolism, LPO has ability to catalyze the transformation of thiocyanate (SCN^-) to hypothiocyanite (OSCN^-) that is an antibacterial agent and the reaction occurs with hydrogen peroxide. In this work, LPO inhibition effects of some antibiotics including cefazolin, oxytetracycline, flunixin meglumine, cefuroxime, tylosin, vancomycin, chloramphenicol and lincomycin were tested. Among the antibiotics cefazolin was indicated the strongest inhibitory efficacy. The half maximal inhibitory concentration (IC₅₀) and the inhibition constant (K_i) values of cefazolin were found as 8.19 and 34.66 µM, respectively. It was shown competitive inhibition. 5-Methyl-1,3,4-thiadiazol-2-yl moiety activity plays a key role in the inhibition mechanism of cefazolin.

Communicated by Ramaswamy H. Sarma

Keywords:

• Lactoperoxidase
• enzyme purification
• antibiotics
• kinetics
• enzyme inhibition

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contribution

R. Kalin and A. Atasever conceived the study. S. Bayrak, and H. Usanmaz performed the experiments related to enzyme purity. S. Gerni and I.N. Ozyurek performed the experiments related to LPO inhibition. M. Karaman performed the molecular docking. H. Ozdemir and I. Gulcin wrote and revised the final version of the paper.