Angular dependence of dipole-dipole-Curie-spin cross-correlation effects in high-spin and low-spin paramagnetic myoglobin

• Main Authors: Pintacuda, Guido, Hohenthanner, Karin, Norbert, M, Otting, Gottfried
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Kluwer Academic Publishers
• Subjects: Keywords: hydrogen; metal; metmyoglobin; nitrogen 15; anisotropy; article; chemical bond; controlled study; crystal structure; dipole; magnetism; mathematical analysis; molecular interaction; nonhuman; nuclear magnetic resonance spectroscopy; prediction; priority j Anistropy of magnetic susceptibility; Dipole-dipole-Curie-spin cross corelation; Long-range angle restraints; Magnetic susceptibility tensor; Paramagnetic relaxation; Sperm-whale myoglobin; Sperm whale
• Online Access: http://hdl.handle.net/1885/85846; https://doi.org/10.1023/A:1024926126239

The 15N-HSQC spectra of low-spin cyano-met-myoglobin and high-spin fluoro-met-myoglobin were assigned and dipole-dipole-Curie-spin cross-correlated relaxation rates measured. These cross-correlation rates originating from the dipolar 1H-15N interaction and the dipolar interaction between the 1H and the Curie spin of the paramagnetic center contain long-range angular information about the orientation of the 1H-15N bond with respect to the iron-1H vector, with information measurable up to 11 Å from the metal for the low-spin complex, and between 10 to 25 Å for the high-spin complex. Comparison of the experimental data with predictions from crystal structure data showed that the anisotropy of the magnetic susceptibility tensor in low spin cyano-met-myoglobin significantly influences the cross-correlated dipole-dipole-Curie-spin relaxation rates.