Naslov
Proton Magnetic Relaxation Dispersion in Human Fluoromethaemoglobin Solutions

Autori
Lahajnar, Gojmir ; Benko, Bojan ; Rutar, V. ; Zupančič, Ivan

Izvornik
International journal of peptide & protein research (0367-8377) 8 (1976), 3; 317-322

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Correlation time ; Frequency dispersion ; Haemoglobin ; Fluoromethaemoglobin ; Proton magnetic relaxation

Sažetak
The solvent proton spin-lattice relaxation time of high spin Fe3+ (S=5/2) human A fluoromethaemoglobin aqueous solutions was measured at 14 Larmor frequencies in the range from 2.2 to 96 MHz. The observed paramagnetic relaxation rates are analysed in terms of the Solomon-Bloembergen theory, with the g-tensor value of 2 based on the consideration of the protein tertiary structure. From the H2O (pH 6) haemoprotein solution relaxation data, tc= (9.3± ; ; 0.3) x 10-10 sec. If the total relaxation rates are corrected for the "outer-sphere" paramagnetic contribution, tc = (6.5± ; ; 0.4) x 10-10 sec. The latter correction is obtained from the p.m.r. of the non-exchangeable aliphatic protons of C2H4(OD)2 added to the D2O-solution of fluoromethaemoglobin. Assuming that single proton transfer is taking place through the protein channel along the axis normal to the haem (g=2), the protein "binding site" is at a distance of 3.93 to 3.98 Å ; ; from the haem Fe3+ ion.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija, Biologija

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