Publication

Light-Induced Pulsed EPR Dipolar Spectroscopy on a Paradigmatic Hemeprotein

Dal Farra, M. G., Richert, S., Martin, C., Larminie, C., Gobbo, M., Bergantino, E., Timmel, C. R., Bowen, A. M. & Di Valentin, M., 2-Apr-2019, In : Chemphyschem. 20, 7, p. 931-935 5 p.

Research output: Contribution to journalArticleAcademicpeer-review

  • Maria Giulia Dal Farra
  • Sabine Richert
  • Caterina Martin
  • Charles Larminie
  • Marina Gobbo
  • Elisabetta Bergantino
  • Christiane R. Timmel
  • Alice M. Bowen
  • Marilena Di Valentin

Light-induced pulsed EPR dipolar spectroscopic methods allow the determination of nanometer distances between paramagnetic sites. Here we employ orthogonal spin labels, a chromophore triplet state and a stable radical, to carry out distance measurements in singly nitroxide-labeled human neuroglobin. We demonstrate that Zn-substitution of neuroglobin, to populate the Zn(II) protoporphyrin IX triplet state, makes it possible to perform light-induced pulsed dipolar experiments on hemeproteins, extending the use of light-induced dipolar spectroscopy to this large class of metalloproteins. The versatility of the method is ensured by the employment of different techniques: relaxation-induced dipolar modulation enhancement (RIDME) is applied for the first time to the photoexcited triplet state. In addition, an alternative pulse scheme for laser-induced magnetic dipole (LaserIMD) spectroscopy, based on the refocused-echo detection sequence, is proposed for accurate zero-time determination and reliable distance analysis.

Original languageEnglish
Pages (from-to)931-935
Number of pages5
JournalChemphyschem
Volume20
Issue number7
Publication statusPublished - 2-Apr-2019
Externally publishedYes

    Keywords

  • DEER, PELDOR, EPR spectroscopy, heme proteins, porphyrinoids, triplet state, NANOMETER DISTANCE MEASUREMENTS, ELECTRON DOUBLE-RESONANCE, SPIN LABELS, TRIPLET-STATE, PROTEIN, MODEL, MN2+, SENSITIVITY

ID: 118595141