Molecular cloning, structural modeling and characterization of a novel glutaminase-free L-asparaginase from Cobetia amphilecti AMI6.

Autor: Farahat MG; Botany and Microbiology Department, Faculty of Science, Cairo University, 12613 Giza, Egypt. Electronic address: farahat@cu.edu.eg., Amr D; Chemistry Department, Faculty of Science, Cairo University, 12613 Giza, Egypt. Electronic address: dina@sci.cu.edu.eg., Galal A; Chemistry Department, Faculty of Science, Cairo University, 12613 Giza, Egypt.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2020 Jan 15; Vol. 143, pp. 685-695. Date of Electronic Publication: 2019 Nov 20.
DOI: 10.1016/j.ijbiomac.2019.10.258
Abstrakt: The exploration of new sources of L-asparaginase with low glutaminase activity is of great interest in both medical and food applications. In the current study, a novel L-asparaginase gene (CobAsnase) from halotolerant Cobetia amphilecti AMI6 was cloned and over-expressed in Escherichia coli. The enzyme had a molecular mass of 37 kDa on SDS-PAGE and dynamic light scattering (DLS) analysis revealed that CobAsnase is a homotetramer in solution. The purified enzyme showed optimum activity at pH and temperature of 7 and 60 °C, respectively, with obvious thermal stability. It exhibited strict substrate specificity towards L-asparagine with no detectable activity on L-glutamine. Pre-treatment of potato slices by CobAsnase prior to frying reduced the acrylamide contents in the processed chips up to 81% compared with untreated control. These results suggest that CobAsnase is a potential candidate for applications in the food industry for mitigation of acrylamide formation in fried potato and baked foods.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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