TEMPONE correlation time

Table 5, Average polymer chain concentration (ape), polymer swellability (S), rotational correlation times of TEMPONE (r) and self-diffusion coefficient of methanol (Zf) in the swollen 2,2% Pd catalysts.

Steinhoff et al. (1989) measured the temperature and hydration dependence of the ESR spectra of hemoglobin spin-labeled at cysteine )8-93. They observed the critical temperature near 200 K, as described above, and the sensitivity of the spectrum to hydration level. Spectrum simulations suggested that there were two types of motion in the dry protein, a fast vibration of the label within a limited motion cone upon the addition of water, a hydration-dependent motion assigned to the fluctuations of the protein, of correlation time 10 sec in samples of high hydration and at 300 K. The temperature dependence of the motional properties of a spin probe (TEMPONE), diffused into hydrated single crystals, closely paralleled the motional properties of the label. This was taken to be evidence for coupling between the dynamical properties of the protein and the adjacent solvent. 

Fig. 21. Values of the correlation time, r, for TEMPONE noncovalently bound to lysozyme in the variable environment as a function of hydration level. Error bar shows the range of values that gives acceptable simulated spectra. Fraction of TEMPONE in the variable environment is 0.5 0.2 at high hydration. From Rupley etal. (1980).

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