STRUCTURAL AND ELECTRONIC PROPERTIES OF NBPT INHIBITOR ATTACHED TO UREASE

Abstract

In this study, the structural and electronic properties of the N-(n-Butyl) Thiophosphoric Triamide (NBPT) inhibitor, in the form of monoamidothiophosphoric acid (MATP), as attached to urease enzyme, has been investigated. These include the electron density, molecular orbitals involved in the interactions, and the whole system’s charge distributions. The difference between the interaction of urease-NBPT and urease-urea was conducted throughout this study. This comparison was crucial to prove the NBPT inhibitor’s mechanism to slow down urea’s hydrolysis in the soil solution. The quantum mechanical calculations were performed at the level theory B3LYP/6-31G(d,p). The urease-NBPT complex has higher interaction energy than the urease-urea complex, in which the interaction energy is –1.6787 eV. The urease-NBPT complex has a lower molecular electronic energy gap than the urease-urea complex, at 0.9527 eV. The graphical representation of HOMO, LUMO, and electrostatic potential maps indicates that the NBPT inhibitor can create favourable interaction with the atoms at urease’s active site.