Effect of ultrasound on the catalytic activity of catalase from yeasts

Objective To study the effect of ultrasound on the activity of catalase(CAT) and its action mechanism.Methods Ultrasound with different parameters was used to treat yeast CAT.Changes of enzyme activity,kinetics,and spectra were detected before and after treatment.Results It indicated that the activity of catalase from yeast (Saccharomyces cerevisiae) could be increased by 126.35% via treatment with ultrasound of 16 kHz and 50 W at 30℃ for 2 min.CAT treated by ultrasound presented higher fluorescence emission intensity.The ultra violet(UV) absorption spectrum had no obvious change after ultrasound treatment.This indicated that the ultrasound treatment did not change the molecular configuration of CAT.But after the treatment,UV differential spectrum showed positive and negative peaks.This indicated that the molecular conformation changed obviously.The results of enzyme kinetics analysis indicated that both Km and Vmax increased after ultrasound treatment.Conclusion Ultrasound with appropriate parameters cna increase the activity of CAT.This misht be caused by the change of conformation of the enzyme molecules caused by ultrasound. Key words: Catalase ;  Ultrasound ;  Spectrum analysis ;  Kinetics analysis ;