Stabilization of Aspergillus flavus urate oxidase enzyme by site-directed mutagenesis

Uricase enzyme, also known as urate oxidase, is a key and important enzyme in thecatabolism of purines and it produces allantoin by catalyzing the reaction process of uric aciddecomposition. In medicine, uricase is utilized as a diagnostic tool to measure uric acid levels in bloodand other biological fluids. Elevated uric acid levels in the blood can lead to conditions such as gout,diabetes, cardiovascular disease, renal nephropathy, and tumor lysis syndrome. Hence, urate oxidasecan serve as a medicinal enzyme to reduce uric acid levels.However, a major challenge withpharmaceutical enzymes like urate oxidase is their low thermal stability under physiological conditions,resulting in reduced enzyme activity above ۲۵ degrees Celsius. Site-directed mutagenesis allows precisemodification of gene and protein function, potentially leading to the creation of a protein with improvedproperties. In a particular study, the enzyme's structure was analyzed using bioinformatics tools, andamino acid ۱۶۴ was selected for mutation due to its location outside the active site and its potential formutation and kinetic and thermodynamic optimization. Using the site-directed mutagenesis method, itwas converted to arginine. The introduction of arginine is expected to create new opportunities forhydrogen and ionic bonds as well as electrostatic bonds in the protein, making it a suitable substitutefor the desired amino acid. This modification is predicted to enhance the stability of the tetramerstructure, which is the active form of the enzyme, due to the creation of new electrostatic, ionic, andhydrogen bonds.

کلیدواژه ها:

urate oxidase ، site-directed mutagenesis ، Stabilization ، uric acid ، Structural bioinformatics