Electron paramagnetic resonance properties of liver fluke (Dicrocoelium dendriticum) nitrosyl hemoglobin

FEBS Letters

Meier, U.Thomas²  Winterhalter, Kaspar H.²  Desideri, Alessandro¹  Di Iorio, Ernesto E.² 

[1] Dipartimento di Fisica, Universita' della Calabria, Arcacavata, Italy;Laboratorium für Biochemie I, Eidgenoessische Technische Hochschule ETH Zentrum, Universitätsstrasse 16, 8092 Zurich, Switzerland

关键词: ERP;    Hemoglobin;    Dicrocoelium dendriticum;    Liver fluke;    Distal histidine;   

DOI  :  10.1016/0014-5793(84)80116-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The electron paramagnetic resonance properties of the nitric oxide derivative of liver fluke (Dicrocoelium dendriticum) hemoglobin (DD-Hb) have been investigated in the pH range from 4.8 to 7.8. In the neutral and alkaline regions the spectra have a rhombic shape, with g_x =2.09, g_y =1.99 and g_z =2.009, and a triplet hyperfine structure of 2.2 mT, due to the nitrogen of the bound NO molecule, in the center resonance. No superhyperfine lines in the g_z region, related to the interaction of the iron with the proximal histidine, are detected, suggesting a large distance between the metal and the N_ϵ of the imidazole. By lowering the pH the EPR spectrum undergoes a reversible change showing a 3-line pattern in the high-field region. Such a spectrum is fully formed at pH 4.8 and is interpreted in terms of a dissociation of the proximal histidine from the heme iron.

【 授权许可】

Unknown