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Comprehensive characterization and molecular insights into the salt tolerance of a Cu, Zn-superoxide dismutase from an Indian Mangrove, Avicennia marina.

Authors :
Sarkar RK
Bhowmik M
Biswas Sarkar M
Sircar G
Bhattacharya K
Source :
Scientific reports [Sci Rep] 2022 Feb 02; Vol. 12 (1), pp. 1745. Date of Electronic Publication: 2022 Feb 02.
Publication Year :
2022

Abstract

Superoxide dismutases are important group of antioxidant metallozyme and play important role in ROS homeostasis in salinity stress. The present study reports the biochemical properties of a salt-tolerant Cu, Zn-superoxide from Avicennia marina (Am_SOD). Am_SOD was purified from the leaf and identified by mass-spectrometry. Recombinant Am_SOD cDNA was bacterially expressed as a homodimeric protein. Enzyme kinetics revealed a high substrate affinity and specific activity of Am_SOD as compared to many earlier reported SODs. An electronic transition in 360-400 nm spectra of Am_SOD is indicative of Cu <superscript>2+</superscript> -binding. Am_SOD activity was potentially inhibited by diethyldithiocarbamate and H <subscript>2</subscript> O <subscript>2</subscript> , a characteristic of Cu, Zn-SOD. Am_SOD exhibited conformational and functional stability at high NaCl concentration as well in alkaline pH. Introgression of Am_SOD in E. coli conferred tolerance to oxidative stress under highly saline condition. Am_SOD was moderately thermostable and retained functional activity at ~ 60 °C. In-silico analyses revealed 5 solvent-accessible N-terminal residues of Am_SOD that were less hydrophobic than those at similar positions of non-halophilic SODs. Substituting these 5 residues with non-halophilic counterparts resulted in > 50% reduction in salt-tolerance of Am_SOD. This indicates a cumulative role of these residues in maintaining low surface hydrophobicity of Am_SOD and consequently high salt tolerance. The molecular information on antioxidant activity and salt-tolerance of Am_SOD may have potential application in biotechnology research. To our knowledge, this is the first report on salt-tolerant SOD from mangrove.<br /> (© 2022. The Author(s).)

Details

Language :
English
ISSN :
2045-2322
Volume :
12
Issue :
1
Database :
MEDLINE
Journal :
Scientific reports
Publication Type :
Academic Journal
Accession number :
35110640
Full Text :
https://doi.org/10.1038/s41598-022-05726-6