Study of the temperature influence on catalase using spin labelling method

Electron paramagnetic resonance (EPR) spectroscopy has been used to study the temperature influence on spin labelled catalase. The measurements were made in the temperature range 300–345 K. The spin label technique allows to observe the structural changes in catalase with increasing temperature. The rotational correlation time of the 3-(2-iodoacetamido)-proxyl spin marker placed in metalloenzyme was determined. The details of ESR spectra contain information on the character of the spin label motion. It indicates the changes in the structure of catalase before the denaturation temperature, determined with dsc microcalorimetry.