Hyperfine-shifted proton resonances

D. Met-Hb A High-Spin Ferric Hyperfine-Shifted Proton Resonances... 

Fig. 9. The linewidth (Av1/2) of a hyperfine-shifted proton resonance of deoxy-Hb A as a function of the resonance frequency (t>o) and of temperature. [From Johnson el al. (1977)].

Fig. 22. Effects of oxygenation on the linewidth of hyperfine-shifted proton resonances of 12% Hb A in 0.1 Af Bis-Tris in D2O at pH 6.6 and 27°C. (A) Fully deoxy sample (-—) (B) 23.5% oxygenation (—) (C) 31.6% oxygenation (—). The intensities of spectra B and C have been prescaled to give the same intensity as spectrum A. [From Viggiano et al. (1979)].

Fig. 25. 250-MHz H NMR spectra of Hb A in both deoxy and oxy forms in 0.1 M Bis-Tris plus 10 mM IHP in D20 at pH 6.6 at 27°C. The resonance at 27 ppm was that of the NMR shift reagent. This reference signal was used for the intensity calibration of the ferrous hyperfine-shifted proton resonances. [From Ho et al. (1982b)].

Fig. 39. 90-MHz H NMR spectra of ferrous hyperfine-shifted proton resonances of deoxyhemoglobins containing mutations in the a,(32 subunit interface in 0.1 Af phosphate in D20 at pH 6.6 and 25°C. [Adapted from Davis et al. (1971) and Ho and Russu (1985)].

Fig. 41. Variation of the ferrous hyperfine-shifted proton resonances of Hb A in 0.1 M Bis-Tris plus 10 mM IHP as a function of oxygenation at pH 6.6 and 27°C A, a-heme resonance at +12 ppm from HDO (data from Viggiano et al., 1979) , a-heme resonance at + 12 ppm from HDO (data from Ho et al., 1982b) , a-heme resonance at + 12 ppm from H20 (data from Viggiano and Ho, 1979) o, p-heme resonance at +18 ppm from HDO (data from Viggiano et al., 1979) , p-heme resonance at + 18 ppm from HDO (data from Hoetal., 1982b) x, p-heme resonance at + 16.9 ppm from HDO (data from Ho et al., 1982b) the curve is the fraction of fully deoxy-Hb tetramers calculated from the data of Tyuma et al. (1973). [From Ho et al. (1982b)].

Fig. 45. 250-MHz H NMR spectra of exchangeable proton resonances and deoxy hyperfine-shifted proton resonances of 15% Hb M Milwaukee (p67Val — Glu, a2p2 ) as a function of the concentration of inositol hexaphosphate in 0.1 M Bis-Tris in H20 at pH 6.6 and 30°C. The spectrum of Hb A is included for comparison. [Adapted from Fung et al. (1977)].

Fig. 48. 250-MHz ferric hyperfine-shifted proton resonances of the abnormal (3 chains of deoxy- and oxy-Hb M Milwaukee ((367 Val — Glu, a2(3 A and D, respectively), and calculated spectra of a singly oxygenated intermediate of Hb M Milwaukee (B and C). Spectra B and C were calculated assuming a Hill coefficient = 1. Test calculation values of n up to 1.4 showed no significant differences in the shape of the calculated spectra. The proton chemical shifts were referenced to HDO. [Adapted from Fung el al. (1977)].

Fig. 49. 600-MHz H NMR spectra of cross-linked mixed-valency asymmetric hybrid hemoglobin (a+CNp)A(aP)cXL, in deoxy and CO forms, in the presence of 0.1 Af phosphate at pH 6.8 and 21°C. (A) Hyperfine-shifted proton resonances in D20 (B) exchangeable and hyperfine-shifted proton resonances in H20. [From Miura and Ho (1982)].

First, comparing the ferrous hyperfine-shifted proton resonances... 

The hyperfine-shifted proton resonance of metmyoglobin and methemoglobin complexes with imidazoles, in particular, 4-nitroimidazole, was studied in order to obtain an insight into the structural features of the iron-bound imidazole [352], The structure of l-(l,3-dihydroxy-2-propyl)-4-nitroimidazoles, so called acyclic nucleosides, has been established by II and 13C NMR [327],... 

Zhang et have studied the heme environment and ligand binding properties of two large membrane proteins (quinol oxidases) containing multiple paramagnetic metal centers. Perturbations of hyperfine-shifted proton resonances were used to probe the chemical changes induced by oxidation-reduction reactions and cyanide addition. 

Sato and Dennison have assigned hyperfine shifted proton resonances of the type I Cu(II) protein, pseudoazurin, by means of saturation transfer experiments on a 1 1 mixture of diamagnetic (Cu(I)) and paramagnetic (Cu(II)) forms of the enzyme. The same authors have also assigned the H NMR spectrum of Co(II)-substituted spinach plastocyanin. 

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