Theoretica chimica acta

, Volume 37, Issue 2, pp 89–104

Molecular structure, quadrupole splitting, and magnetic susceptibility of iron in deoxygenated myoglobin and hemoglobin

Authors

  • Alfred Trautwein
    • Fachbereich Angewandte PhysikUniversität des Saarlandes
    • Fachbereich 12-1 Angewandte Physik Universität des Saarlandes
  • Reinhart Zimmermann
    • Physikalisches Institut IIUniversität Erlangen
  • Frank E. Harris
    • Department of PhysicsUniversity of Utah
Commentationes

DOI: 10.1007/BF00549562

Cite this article as:
Trautwein, A., Zimmermann, R. & Harris, F.E. Theoret. Chim. Acta (1975) 37: 89. doi:10.1007/BF00549562

Abstract

For three stereo-structural models of deoxymyoglobin (Mb) and deoxyhemoglobin (Hb) we derive electronic configurations and their mutual spin-orbit coupling. From the temperature dependent molecular electric field gradient (EFG) tensor we calculate temperature dependent quadrupole splittings, ΔEq(T), asymmetry parameters, η(T), and orientations of the EFG component Vzz(T) with respect to the heme group. Comparing theoretical and experimental data we find a molecular electronic structure, which then is used to compute temperature dependent magnetic susceptibilities, χ(T). Theoretical and experimental χ(T) data are in reasonable agreement. From the consistency of our model calculations with experimental results we conclude that iron in Mb and Hb probably is pentacoordinated and considerably out of the heme plane by 0.4–0.8 Å.

Key words

Myoglobin, deoxygenated, quadrupole splittingHemoglobin, deoxygenated, quadrupole splitting

Copyright information

© Springer-Verlag 1975