000132323 001__ 132323
000132323 005__ 20240301161208.0
000132323 0247_ $$2doi$$a10.3390/molecules29020518
000132323 0248_ $$2sideral$$a137446
000132323 037__ $$aART-2024-137446
000132323 041__ $$aeng
000132323 100__ $$0(orcid)0000-0002-5431-2371$$aFamulari, Antonino
000132323 245__ $$aHeme spin distribution in the Substrate-Free and Inhibited Novel CYP116B5hd: A multifrequency hyperfine sublevel correlation (HYSCORE) study
000132323 260__ $$c2024
000132323 5060_ $$aAccess copy available to the general public$$fUnrestricted
000132323 5203_ $$aThe cytochrome P450 family consists of ubiquitous monooxygenases with the potential to perform a wide variety of catalytic applications. Among the members of this family, CYP116B5hd shows a very prominent resistance to peracid damage, a property that makes it a promising tool for fine chemical synthesis using the peroxide shunt. In this meticulous study, we use hyperfine spectroscopy with a multifrequency approach (X- and Q-band) to characterize in detail the electronic structure of the heme iron of CYP116B5hd in the resting state, which provides structural details about its active site. The hyperfine dipole–dipole interaction between the electron and proton nuclear spins allows for the locating of two different protons from the coordinated water and a beta proton from the cysteine axial ligand of heme iron with respect to the magnetic axes centered on the iron. Additionally, since new anti-cancer therapies target the inhibition of P450s, here we use the CYP116B5hd system—imidazole as a model for studying cytochrome P450 inhibition by an azo compound. The effects of the inhibition of protein by imidazole in the active-site geometry and electron spin distribution are presented. The binding of imidazole to CYP116B5hd results in an imidazole–nitrogen axial coordination and a low-spin heme FeIII. HYSCORE experiments were used to detect the hyperfine interactions. The combined interpretation of the gyromagnetic tensor and the hyperfine and quadrupole tensors of magnetic nuclei coupled to the iron electron spin allowed us to obtain a precise picture of the active-site geometry, including the orientation of the semi-occupied orbitals and magnetic axes, which coincide with the porphyrin N-Fe-N axes. The electronic structure of the iron does not seem to be affected by imidazole binding. Two different possible coordination geometries of the axial imidazole were observed. The angles between gx (coinciding with one of the N-Fe-N axes) and the projection of the imidazole plane on the heme were determined to be −60° and −25° for each of the two possibilities via measurement of the hyperfine structure of the axially coordinated 14N.
000132323 536__ $$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
000132323 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000132323 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000132323 700__ $$aCorreddu, Danilo
000132323 700__ $$aDi Nardo, Giovanna
000132323 700__ $$aGilardi, Gianfranco
000132323 700__ $$aMitrikas, George
000132323 700__ $$aChiesa, Mario
000132323 700__ $$0(orcid)0000-0002-1827-1250$$aGarcía-Rubio, Inés
000132323 773__ $$g29, 2 (2024), 518$$pMolecules (Basel, Online)$$tMolecules$$x1420-3049
000132323 787__ $$tHeme Spin Distribution in the Substrate-Free and Inhibited Novel CYP116B5hd: A Multifrequency HYSCORE Study [Data set]$$w10.5281/zenodo.10535347
000132323 8564_ $$s6418315$$uhttps://zaguan.unizar.es/record/132323/files/texto_completo.pdf$$yVersión publicada
000132323 8564_ $$s2689845$$uhttps://zaguan.unizar.es/record/132323/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000132323 909CO $$ooai:zaguan.unizar.es:132323$$particulos$$pdriver
000132323 951__ $$a2024-03-01-14:54:50
000132323 980__ $$aARTICLE