ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
SUMMARY —Aqueous solutions of purified horseradish peroxidase lost enzymic activity not only during irradiation with gamma rays but also after irradiation. The higher the dose of irradiation, the greater the rate of post-irradiation inactivation. Enzyme activity loss after irradiation increased at higher temperatures of post-irradiation storage. Adjusting the pH of the irradiated enzyme solution to 9 resulted in greater inactivation than adjusting to pH 5 or 7. When the enzyme solution was diluted before irradiation the inactivation proceeded more rapidly after irradiation than in the more concentrated solution. When, however, the already irradiated enzyme was diluted, it was the concentrated enzyme solution that lost more activity. Glycerol added to irradiated enzyme diminished rate of inactivation. Irradiating a frozen enzyme solution resulted in very little or no loss of activity during post-irradiation storage. Neither irradiated water nor irradiated enzyme solution affected the activity of non-irradiated enzyme mixed with them. The following mechanism for the post-irradiation inactivation of HRPO is proposed: A portion of the enzyme which is not inactivated during irradiation is modified so as to result in subsequent inactivation by reacting with itself.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1971.tb03313.x
