Recombinant Expression and Functional Assessment of Uricase from a Pertinent Origin of the Enzyme, Streptomyces sp. Strain 17-1

Document Type : Research Paper

Authors

1 MSc of Cellular and Molecular Biology, University of Science and Culture, Tehran, Iran

2 Molecular Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Iran

3 Deprtment of Biology, Faculty of Science, University of Guilan, Rasht, Iran

4 MSc of Genetics, Faculty of Biology, University of Kharazmi, Tehran, Iran

5 Microorganism Bank. Iranian Biological Resource Center. ACECR, Tehran, Iran

6 Department of Microbiology, Faculty of Biology, University of Tehran, Tehran, Iran

7 Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.

8 Department of Molecular and Cellular Biology, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR Tehran, Iran

Abstract

Background: Uricase or urate oxidase, as a therapeutic enzyme, is extensively applied to oxidize accumulated uric acid
in the body to soluble form to treat related illnesses.
Objectives: This study was conducted with the aim of searching for potential sources of uricase-producing Streptomyces
from Eshtehard salt desert in Alborz province, Iran and heterologous expression, purification and functional assay of the
enzyme.
Materials and Methods: Main screening was conducted by cultivation of the strains on a medium enriched with 0.3 percent (w/v) uric acid. The uricase gene from the most potent strain was then recombinantly expressed in E. coli BL21 (DL3)
Results:Out of the tested strains, only seven showed uricase activity. The highest level of native uricase activity (11.5735
U.mL-1) belonged to strain 17-1, which had the closest similarity to Streptomyces nigra. A recombinant uricase with
a molecular mass of approximately 38 kDa was produced. The purified uricase exhibited a specific activity of about
28.29±0.59 U.mg-1, which is among the highest level of uricase activity reported by other studies
Conclusions: This enzyme is a promising candidate for further applicable investigations and large-scale production in
terms of its large volume of soluble expression and selective competitive activity.

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