L'Effet des Radiations Électromagnétiques sur les Protéines I. Hydrolyse enzymatique de sérumalbumine aprés irradiation gamma en solution aqueuse
✍ Scribed by C. Colson; E. Fredericq
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2010
- Weight
- 441 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0037-9646
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Bovine serumalbumin has been irradiated in aqueous solutions by gamma rays from a ^60^Co source, at dose rates varying between 5,000 and 60,000 rad per hour. An increase in absorbancy is brought about in the absorption band of aromatic aminoacids.
A moderate increase in asymmetry is evidenced by viscosity measurements at total doses below 100,000 rad. For high doses, asymmetry strongly increases and precipitation takes place.
The hydrolysis of irradiated samples by pepsin, trypsin and chymotrypsin has been measured by titration with a pH‐stat or by precipitation with trichloracetic acid. It was found that the rate of hydrolysis by pepsin and chymotrypsin decreased in proportion to the time of irradiation. This was attributed to the modifications produced in aromatic rings by irradiation, since the enzymes used are specific for bonds neighboring such aminoacids. On the contrary, trypsin, which does not have these requirements, is more active on irradiated samples. This could be related, partly at least, to the partial denaturation brought about in serumalbumin by gamma rays.