000171045 001__ 171045
000171045 005__ 20260505142650.0
000171045 0247_ $$2doi$$a10.1039/d6dt00171h
000171045 0248_ $$2sideral$$a149145
000171045 037__ $$aART-2026-149145
000171045 041__ $$aeng
000171045 100__ $$aSerra, Ilenia
000171045 245__ $$aNitrite binding modes in ferric heme proteins probed by HYSCORE spectroscopy
000171045 260__ $$c2026
000171045 5060_ $$aAccess copy available to the general public$$fUnrestricted
000171045 5203_ $$aNitrite plays a fundamental role in the environmental nitrogen cycle and various biochemical reactions. Heme proteins such as globins and peroxidases, often participate in nitrite-mediated pathways, sparking interest in the coordination geometry of nitrite to the heme iron. In most cases, nitrite binds the ferric heme iron via the nitrogen atom (N-nitro mode), while for myoglobin and hemoglobin a less common O-nitrito ligation through one oxygen atom was reported. Our previous study on nitrite binding to the heme-containing enzyme chlorite dismutase (Cld) using continuous-wave electron paramagnetic resonance and crystal-field theory, supported by molecular dynamics simulations, suggested the coexistence of both O-nitrito and N-nitro ligation modes. Here, we present an in-depth hyperfine sublevel correlation (HYSCORE) analysis of NO2-ligated ferric horse heart myoglobin, a Clade-II Cld from Cyanothece sp. PCC7425 and a Clade-I Cld from Magnetospirillum sp. 15N-labelled nitrite was used to discriminate the signals ascribed to the nitrogen nucleus of nitrite from the endogenous N nuclei. The O-nitrito and N-nitro modes can be distinguished based on the nitrite nitrogen hyperfine coupling. Moreover, we describe a distinct HYSCORE spectral fingerprint for the O-nitrito binding mode which can be used as direct evidence of the ligation mode without further detailed analysis. Together, these results provide a generally applicable EPR/HYSCORE-based tool for (bio)inorganic nitrite coordination chemistry of heme systems, enabling more reliable interpretation of nitrite reactivity and mechanism in heme-based catalysts and nitrite-processing enzymes.
000171045 536__ $$9info:eu-repo/grantAgreement/ES/DGA/E09-23R$$9info:eu-repo/grantAgreement/EC/H2020/813209/EU/Paramagnetic Species in Catalysis Research. A Unified Approach Towards Heterogeneous, Homogeneous and Enzyme Catalysis/PARACAT$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 813209-PARACAT$$9info:eu-repo/grantAgreement/ES/MICINN/PID2021-127287NB-I00$$9info:eu-repo/grantAgreement/ES/MICIU/CEX2023-001286-S
000171045 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttps://creativecommons.org/licenses/by/4.0/deed.es
000171045 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000171045 700__ $$aSchmidt, Daniel
000171045 700__ $$aFurtmüller, Paul G.
000171045 700__ $$aGonzález, Pablo J.
000171045 700__ $$aObinger, Christian
000171045 700__ $$aVan Doorslaer, Sabine
000171045 700__ $$0(orcid)0000-0002-1827-1250$$aGarcía-Rubio, Inés
000171045 773__ $$g55, 14 (2026), 5769-5779$$pDalton Trans.$$tDalton Transactions$$x1477-9226
000171045 787__ $$tSupplementary information$$whttps://www.rsc.org/suppdata/d6/dt/d6dt00171h/d6dt00171h1.pdf
000171045 8564_ $$s1613824$$uhttps://zaguan.unizar.es/record/171045/files/texto_completo.pdf$$yVersión publicada
000171045 8564_ $$s2708062$$uhttps://zaguan.unizar.es/record/171045/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000171045 909CO $$ooai:zaguan.unizar.es:171045$$particulos$$pdriver
000171045 951__ $$a2026-05-05-13:36:26
000171045 980__ $$aARTICLE