Comparison of Radiation-induced Radical Yields in Short Peptides and Constituent Amino Acids by Detection of Trapped Oxygen Isotope ¹⁸O

Summary

This report compares the radiosensitivity of small polypeptides and constituent isolated amino acids using a novel technical approach. The radiation-induced oxygen isotope ¹⁸O trapping was measured by means of nuclear reactions. Most of the peptides reveal a higher sensitivity than a mixture of their constituent amino acids. This observation can be rationalized with a simple model which implies intramolecular energy transfer.

• Peptides
• oxygen trapping
• radical yields
• intramolecular energy transfer