Biodynamic and Thermodynamic Study of Alanine Aminopeptide (AAP) Partially Purified from the Urine of Patients with Chronic Renal Injury

Alanine aminotransferase (AAP) activity was measured in the urine of healthy individuals, with an activity level of 7.49 ≤ 2.76 IU/L. In infected individuals, the activity level was 24.83 ≤ 9.66 IU/L. The results showed elevated AAP activity in the urine of 97% of patients compared to healthy individuals. AAP was purified from the urine of patients with renal failure using gel filtration chromatography with Sephadex G-50 filtration gel. AAP was separated from the urine of patients with renal failure using ion-exchange chromatography with DEAE-Sephadex A-50 resin. It was observed that the isoform obeys the Arrhenius equation up to 37 m⁻¹, and Ea and Q10 were determined. A thermodynamic study was performed on the binding of the substrate (alanine-4-naturoanilide) to the alanine aminopeptide (AAP) isoforms. Using the van't Hoff and Arrhenius equations, the thermodynamic coefficients for the standard state (ΔSO, ΔGO, ΔHO) and the transition state (ΔS*, ΔG*, ΔH*) were determined.