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Leu169Trp substitution in MnSOD from Staphylococcus equorum created an active new form of similar resistance to UVC irradiation
Retnoningrum D.S.a, Arumsari S.a,c, Desi E.S.a, Tandra Y.S.b, Artarini A.a, Ismaya W.T.b
a Laboratory of Pharmaceutical Biotechnology, School of Pharmacy, Bandung Institute of Technology, Bandung, 40132, Indonesia
b Dexa Laboratories of Biomolecular Sciences, Kawasan Industri Jababeka II, Cikarang, 17550, Indonesia
c Molecular Biology and Proteomics Core Facilities, Indonesia Medical Education and Research Institute (IMERI), Faculty of Medicine, University of Indonesia, Jakarta, 10430, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© 2018 Elsevier Inc.Manganese superoxide dismutase from Staphylococcus equorum (MnSODSeq) maintains its activity after up to 45 minutes of UVC radiation. The enzyme occurs in a dimeric form that likely contributes to its activity and stability. Therefore, maintaining the dimeric form could be a way to improve the enzyme’s stability. One of the main interactions for dimer formation occurs between Tyr168 and His31, of which the latter is also involved in the enzymatic reaction. UVC radiation may cause alterations in the electronic structure of the phenolic ring in the Tyr168 side chain: this may disrupt the Tyr168-His31 pairing and lead to enzyme instability and/or activity loss. In this report, a Leu169Trp substitution was carried out to protect the Tyr168 residue by introducing an amino acid with an aromatic side chain for better photon absorption of the UV light. Interestingly, although the substitution appeared to have a minor effect on enzyme stability and activity upon UVC irradiation, the melting temperature (TM) of the Leu169Trp mutant was different. Unlike the native protein, the TM of the mutant had not changed after UV irradiation. Thus, our effort to extend the resistance to UVC radiation was not successful, but we have discovered a biologically active new form. The present finding provides evidence that MnSODSeq maintains most of its activity and resistance to UVC irradiation as long as the dimer and its glutamate-bridge are intact, despite an alteration that destabilizes its monomeric structure. The present finding further unravels the relationship between the structure of the enzyme and its activity. Furthermore, the results may provide further insight in how to modify the enzyme to improve its characteristics for application in medicine or cosmetics.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Aromatic side chains,Dimeric interaction,Enzyme stability,Manganese superoxide dismutase,Monomeric structures,Photon absorptions,Super oxide dismutase,UVC protection,Amino Acid Substitution,Binding Sites,Enzyme Stability,Leucine,Models, Molecular,Mutagenesis, Site-Directed,Mutation,Oxidation-Reduction,Protein Conformation,Radiation Tolerance,Staphylococcus,Superoxide Dismutase,Tryptophan,Ultraviolet Rays[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Dimeric interaction,Enzyme stability,Superoxide dismutase,UVC protection[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text]This work is supported by Program Riset Inovasi ITB (2016). We thank Dr. H. J. Doddema for editing the manuscript.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1016/j.enzmictec.2018.06.015[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]