131557 20240319080954.0 doi 10.1016/j.jinorgbio.2021.111689 sideral 128235 ART-2022-128235 eng Serra, I. Impact of the dynamics of the catalytic arginine on nitrite and chlorite binding by dimeric chlorite dismutase 2022 Chlorite dismutases (Clds) are heme b containing oxidoreductases able to decompose chlorite to chloride and molecular oxygen. This work analyses the impact of the distal, flexible and catalytic arginine on the binding of anionic angulate ligands like nitrite and the substrate chlorite. Dimeric Cld from Cyanothece sp. PCC7425 was used as a model enzyme. We have investigated wild-type CCld having the distal catalytic R127 hydrogen-bonded to glutamine Q74 and variants with R127 (i) being arrested in a salt-bridge with a glutamate (Q74E), (ii) being fully flexible (Q74V) or (iii) substituted by either alanine (R127A) or lysine (R127K). We present the electronic and spectral signatures of the high-spin ferric proteins and the corresponding low-spin nitrite complexes elucidated by UV–visible, circular dichroism and electron paramagnetic resonance spectroscopies. Furthermore, we demonstrate the impact of the dynamics of R127 on the thermal stability of the respective nitrite adducts and present the X-ray crystal structures of the nitrite complexes of wild-type CCld and the variants Q74V, Q74E and R127A. In addition, the molecular dynamics (MD) and the binding modi of nitrite and chlorite to the ferric wild-type enzyme and the mutant proteins and the interaction of the oxoanions with R127 have been analysed by MD simulations. The findings are discussed with respect to the role(s) of R127 in ligand and chlorite binding and substrate degradation. info:eu-repo/grantAgreement/EC/H2020/813209/EU/Paramagnetic Species in Catalysis Research. A Unified Approach Towards Heterogeneous, Homogeneous and Enzyme Catalysis/PARACAT This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 813209-PARACAT info:eu-repo/semantics/closedAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 3.9 2022 CHEMISTRY, INORGANIC & NUCLEAR 8 / 42 = 0.19 2022 Q1 T1 BIOCHEMISTRY & MOLECULAR BIOLOGY 126 / 285 = 0.442 2022 Q2 T2 0.646 2022 Inorganic Chemistry 2022 Q1 Biochemistry 2022 Q2 7.0 2022 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Schmidt, D. Pfanzagl, V. Mlynek, G. Hofbauer, S. Djinovic-Carugo, K. Furtmüller, P. G. García-Rubio, Inés Universidad de Zaragoza (orcid)0000-0002-1827-1250 Van Doorslaer, S. Obinger, C. 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 227 (2022), 111689 [15 pp.] J. inorg. biochem. Journal of Inorganic Biochemistry 0162-0134 3283951 http://zaguan.unizar.es/record/131557/files/texto_completo.pdf Postprint 2373712 http://zaguan.unizar.es/record/131557/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:131557 articulos driver 2024-03-18-13:26:41 ARTICLE