QM study on inhibition mechanism of human carbonic anhydrase (II) enzyme by Boricacid derivatives inhibitors: Kinetic and thermodynamic investigation

In this research, the electronic structure and inhibition mechanism of some boric acid derivatives as new inhibitors forthe inhibition of human α -carbonic anhydrase (ΙΙ) enzyme, α-hCA(ΙΙ), have been investigated using quantum mechanicalcalculations. At the first step, selective inhibitors and enzyme model were optimized using B۳LYP/۶-۳۱۱+G** method intwo gas and lipoprotein solvent phase, and then the interaction between enzyme and inhibitors was investigated. The usedenzyme model in this research including the zinc ion (Zn۲+) in the catalytic center of enzyme active site with four coordinationnumber which is connected to three histidine amino acids and one hydroxyl ion in the active form of the enzyme. Scancalculation was used to find the best interaction distance between enzyme and inhibitor. Based on the results of scanningcalculations, a square-shaped transition state is formed and then by passing through an intermediate the reaction productis formed. Finally, the results of calculations show that [۱,۱-biphenyl]-۴-yl boronic acid molecule with the smallest energybarrier (۵۴.۶۸ kcal/mol ) and (E)-(۴-methylstyryl) boronic acid with the highest energy barrier (۶۲.۱۴ kcal/mol), are predictedas the strongest and weakest inhibitors, which is in good agreement with the experimental results.

کلیدواژه ها:

Carbonic anhydrase ، Inhibitor ، Boronic acid ، Quantum mechanical calculations ، Thermodynamic parameters