Direct effects of radiation on the avidin-biotin system. Absence of energy transfer.
Frozen solutions of biotinylated glucose-6-phosphate dehydrogenase and fluorescently tagged avidin were exposed to high energy ionizing radiation. Parallel experiments with peroxidase coupled to streptavidin and with biotinylated phycoerythrin were also performed. The loss of function of each compound was analyzed according to target theory. Target analysis revealed that the radiation-sensitive mass associated with the enzymatic activity and that associated with the fluorescence were unchanged by irradiation in the strongly coupled state. Therefore the noncovalent bonds between biotin and avidin do not permit the transfer of radiation-deposited energy in amounts sufficient to destroy the activity of apposing molecule.
Laboratory of Physical Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892.
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Kempner
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JH
Miller
D001360:Avidin / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000528:radiation effects*; D001710:Biotin / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004735:Energy Transfer; D005456:Fluorescent Dyes; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism / Q000528:radiation effects*; D006735:Horseradish Peroxidase / Q000378:metabolism / Q000528:radiation effects; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013050:Spectrometry, Fluorescence; D019809:Streptavidin
D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D001360:Avidin; D001710:Biotin; D019809:Streptavidin; D005954:Glucosephosphate Dehydrogenase; D006735:Horseradish Peroxidase