Oxygen Effect as an Explanation of Differences between the Action of α-Particles and X- or γ-Rays on Aqueous Solutions of Amino-acids and Proteins
Differences in extinction coefficients between irradiated and unirradiated solutions for 2 x 10⁻⁴ M tryptophan irradiated with gamma rays (66400 rads) in the absence of air, in the presence of air, and in the presence of 10⁻³ M H₂O₂ (air absent) are compared with previously obtained results. Results with gamma rays in the absence of oxygen are in reasonable agreement with other resuits, while results in the presence of oxygen or H/sub 2/O/sub 2/ show similar qualitative features with alpha particles under nitrogen, that is, compared with the result of x or gamma irradiation in the absence of oxygen, they show a larger drop in extinction coefficient near the tryptophan absorption peaks at 279 and 287 M mu , a larger rise below about 270 m mu , and an increased production of a substance or substances absorbing above 300 m mu . This suggests that the alpha particles are acting through the formation of oxygen and/or hydrogen peroxide from the water, simultaneously with free radicals. The loss of tryptophan and the ammonia yield from gamma irradiated tryptophan were also measured. (P.C.H.)
- Research Organization:
- Imperial Coll. of Science and Tech., London
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-16-029020
- OSTI ID:
- 4779128
- Journal Information:
- Nature (London), Vol. 195, Issue 4843; Other Information: Orig. Receipt Date: 31-DEC-62; ISSN 0028-0836
- Publisher:
- Nature Publishing Group
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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