THE INACTIVATION OF TRYPSIN BY X-RAYS

Area of Science:

• Biochemistry
• Radiation Biology
• Enzymology

Background:

• Trypsin is a crucial digestive enzyme.
• Understanding enzyme inactivation mechanisms is vital for various applications.
• Previous studies explored radiation effects on biological molecules.

Purpose of the Study:

• To investigate the inactivating effects of soft x-rays on trypsin.
• To compare x-ray inactivation with spontaneous heat inactivation.
• To elucidate the mechanism of trypsin inactivation by radiation.

Main Methods:

• Studying trypsin solutions at different concentrations.
• Exposing trypsin to soft x-ray radiation of constant intensity.
• Measuring enzyme activity to quantify inactivation.
• Comparing experimental results with existing data on beta-ray inactivation.

Main Results:

• Soft x-ray inactivation of trypsin parallels spontaneous heat inactivation.
• Inactivation is primarily observed in free or active trypsin.
• Trypsin inactivation follows a monomolecular reaction law under constant radiation intensity.
• Ionization is identified as the primary mechanism responsible for inactivation.

Conclusions:

• Soft x-ray radiation inactivates trypsin through a process similar to heat inactivation.
• The inactivation mechanism is dependent on ionization, likely involving electrical neutralization of the trypsin ion.
• The findings support the hypothesis that ionization is the sole determinant of radiation-induced enzyme inactivation.