"Resurrected" human-source urate oxidase with high uricolytic activity and stability

2021 ◽  
pp. 109852
Author(s):  
Jiang Nan ◽  
Chunqin Xu ◽  
Linhan Zhang ◽  
Jianhua Chen
Keyword(s):  
Urate Oxidase ◽  
Human Source

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

scholarly journals Enhancement of Thermostability of Aspergillus flavus Urate Oxidase by Immobilization on the Ni-Based Magnetic Metal–Organic Framework

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1759
Author(s):  
Neda Motamedi ◽  
Mahmood Barani ◽  
Azadeh Lohrasbi-Nejad ◽  
Mojtaba Mortazavi ◽  
Ali Riahi-Medvar ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Metal Organic Framework ◽  
Urate Oxidase ◽  
Significant Activity ◽  
Original Activity ◽  
Long Term Stability ◽  
Magnetic Metal ◽  
Metal Organic ◽  
Almost All ◽  
Organic Framework

The improvement in the enzyme activity of Aspergillus flavus urate oxidase (Uox) was attained by immobilizing it on the surface of a Ni-based magnetic metal–organic framework (NimMOF) nanomaterial; physicochemical properties of NimMOF and its application as an enzyme stabilizing support were evaluated, which revealed a significant improvement in its stability upon immobilization on NimMOF (Uox@NimMOF). It was affirmed that while the free Uox enzyme lost almost all of its activity at ~40–45 °C, the immobilized Uox@NimMOF retained around 60% of its original activity, even retaining significant activity at 70 °C. The activation energy (Ea) of the enzyme was calculated to be ~58.81 kJ mol−1 after stabilization, which is approximately half of the naked Uox enzyme. Furthermore, the external spectroscopy showed that the MOF nanomaterials can be coated by hydrophobic areas of the Uox enzyme, and the immobilized enzyme was active over a broad range of pH and temperatures, which bodes well for the thermal and long-term stability of the immobilized Uox on NimMOF.

Crystal Structure of Urate Oxidase from Bacillus Subtilis 168

2019 ◽  
Vol 64 (7) ◽  
pp. 1126-1133 ◽  
Author(s):  
A. Nayab ◽  
S. A. Moududee ◽  
Y. Shi ◽  
Y. Jiang ◽  
Q. Gong
Keyword(s):  
Crystal Structure ◽  
Bacillus Subtilis ◽  
Urate Oxidase ◽  
Bacillus Subtilis 168

Glucocorticoid regulation of rat liver urate oxidase

1991 ◽  
Vol 47 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Linda Symons Raab ◽  
Glenn L. Decker ◽  
Adam J. Jonas ◽  
Marcia A. Kaetzel ◽  
John R. Dedman
Keyword(s):  
Rat Liver ◽  
Urate Oxidase

scholarly journals Molecular Elucidation of a Urate Oxidase from Deinococcus radiodurans for Hyperuricemia and Gout Therapy

2021 ◽  
Vol 22 (11) ◽  
pp. 5611
Author(s):  
Yi-Chih Chiu ◽  
Ting-Syuan Hsu ◽  
Chen-Yu Huang ◽  
Chun-Hua Hsu
Keyword(s):  
Uric Acid ◽  
High Stability ◽  
Deinococcus Radiodurans ◽  
Catalytic Efficiency ◽  
Enzyme Characterization ◽  
Urate Oxidase ◽  
Medical Applications ◽  
Physiological Conditions ◽  
Extremophile Microorganism ◽  
Mesophilic Conditions

Urate oxidase initiates the uric acid degradation pathways and is extensively used for protein drug development for gout therapy and serum uric acid diagnosis. We first present the biochemical and structural elucidation of a urate oxidase from the extremophile microorganism Deinococcus radiodurans (DrUox). From enzyme characterization, DrUox showed optimal catalytic ability at 30 °C and pH 9.0 with high stability under physiological conditions. Only the Mg2+ ion moderately elevated its activity, which indicates the characteristic of the cofactor-free urate oxidase family. Of note, DrUox is thermostable in mesophilic conditions. It retains almost 100% activity when incubated at 25 °C and 37 °C for 24 h. In this study, we characterized a thermostable urate oxidase, DrUox with high catalytic efficiency and thermal stability, which strengthens its potential for medical applications.

Effect and Mechanism of Total Saponin of Dioscorea on Animal Experimental Hyperuricemia

2006 ◽  
Vol 34 (01) ◽  
pp. 77-85 ◽  
Author(s):  
Guang-Liang Chen ◽  
Wei Wei ◽  
Shu-Yun Xu
Keyword(s):  
Uric Acid ◽  
Serum Uric Acid ◽  
Acid Concentration ◽  
Serum Uric Acid Level ◽  
Urate Oxidase ◽  
Uric Acid Concentration ◽  
Total Saponin ◽  
Test Kit ◽  
Serum Uric Acid Concentration ◽  
Potassium Oxonate

In this study, we investigated the effects and mechanisms of Total Saponin of Dioscorea (TSD) on animal experimental hyperuricemia. Mouse and rat hyperuricemic models were made by orally administering yeast extract paste once a day (30 and 20 g/kg, respectively), for 7 days. Yeast would disturb normal purine metabolism by increasing xanthine oxidase (XOD) activity and generating large quantities of uric acid. This model is similar to human hyperuricemia, which is induced by high-protein diets, due to a purine and nucleic acid metabolic disturbance. Another mouse hyperuricemia model was generated by intraperitoneal injection once with uric acid 250 mg/kg or potassium oxonate 300 mg/kg. Potassium oxonate, a urate oxidase inhibitor, can raise the serum uric acid level by inhibiting the decomposition of uric acid. Likewise, injecting uric acid can also increase serum uric acid concentration. The concentration of uric acid in serum or urine was detected by the phosphotungstic acid method, and the activity of XOD was assayed by a test kit. The results showed that TSD (240, 120 and 60 mg/kg, ig) could significantly lower the level of serum uric acid in hyperuricemic mice. TSD (120 and 60 mg/kg, ig) could also lower the level of serum uric acid in hyperuricemic rats, reduce the activity of XOD in the serum and liver of hyperuricemic rats, and increase the level of urine uric acid concentration as well as 24-hour total uric acid excretion. In conclusion, TSD possesses a potent anti-hyperuricemic effect on hyperuricemic animals, and the mechanism may be relevant in accelerating the excretion and decreasing the production of uric acid.

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