Spin-dependent O2 binding to hemoglobin
College of Science
We report results of our study on the mechanism of spin-dependent O2 binding to hemoglobin, which we represent as FePIm (Fe = iron, P = porphyrin, Im = imidazole). This involves the transition between two states, viz., the oxyhemoglobin state and the deoxyhemoglobin state. The deoxyhemoglobin state pertains to FePIm and a free O2 molecule, while the oxyhemoglobin state pertains to an O2 bound to FePIm. The deoxyhemoglobin and oxyhemoglobin systems have triplet and singlet total magnetizations, respectively. We found that a spin transition from triplet to quintet to singlet mediates the O2 binding process, and this accelerates the reaction. We also found that the position of the Fe atom out of the porphyrin plane is an important indicator of O2 affinity. Copyright © 2018 American Chemical Society.
Digitial Object Identifier (DOI)
Kurokawa, D., Gueriba, J., & Diño, W. A. (2018). Spin-dependent O2 binding to hemoglobin. ACS Omega, 3 (8), 9241-9245. https://doi.org/10.1021/acsomega.8b00879
Oxyhemoglobin; Hemoglobin; Oxygen in the body