Neuroglobin Provides a Convenient Scaffold to Investigate the Triplet-State Properties of Porphyrins by Time-Resolved EPR Spectroscopy and Magnetophotoselection

Abstract The photo-excited triplet state of Zn-protoporphyrin IX located in the heme pocket human neuroglobin has been investigated by time-resolved EPR coupled to magnetophotoselection. protein matrix compared with model complex organic glass, considering both non-coordinating and coordinating solvent mixtures. plays an important role stabilizing coordination embedded chromophore, resulting a more homogeneous environment relative that chromophore glassy solvent, even presence axial nitrogenous ligand like pyridine. spectral parameters point out slow Jahn–Teller interconversion between slightly different states, matrix. EPR-magnetophotoselection allows us propose reinterpretation assignment Q bands electronic absorption spectrum.