TY - JOUR
T1 - Light‐Induced Pulsed EPR Dipolar Spectroscopy on a Paradigmatic Hemeprotein
AU - Dal Farra, M-G
AU - Richert, S
AU - Martin, C
AU - Larminie, C
AU - Gobbo, Marina
AU - Bergantino, E
AU - Timmel, Christiane R
AU - Bowen, Alice
AU - Di Valentin, Marilena
PY - 2019/2/28
Y1 - 2019/2/28
N2 - 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.
AB - 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.
U2 - 10.1002/cphc.201900139
DO - 10.1002/cphc.201900139
M3 - Article
SN - 1439-7641
VL - 20
JO - Chemphyschem : a European journal of chemical physics and physical chemistry
JF - Chemphyschem : a European journal of chemical physics and physical chemistry
IS - 7
ER -