TRANSFER OF RADIATION-INDUCED UNPAIRED SPINS FROM PROTEINS TO SULFUR COMPOUNDS

Journal Article · Fri Feb 01 04:00:00 EST 1963 · Radiation Res.

DOI:https://doi.org/10.2307/3571436· OSTI ID:4712553

Henriksen, T; Sanner, T; Pihl, A

The interaction between crystalline proteins and small molecular thiols and disulfides irradiated in the dry state was studied by ESR spectroscopy. The substances were irradiated at 77 un. Concent 85% K, singly and in mixtures, and the samples were subsequently subjected to stepwise controlled heattreatment. At 77 un. Concent 85% K the radical yield of irradiated mixtures of proteins with sulfur compounds was equal to weighted average of those observed when the two components were irradiated separately. When the irradiated mixtures were heat- treated, sulfur radicals were formed to a far greater extent than would be expected on the assumption that no interaction occurs between the components. Since sulfur radicals in penicillamine can be distinguished from those induced in proteins, it could be demonstrated that unpaired spins, initially induced in the protein, became transferred to the sulfur of the penicillamine. Experiments with S/sup 35/labled cysteamine demonstrated that a small number of cysteamine residues became covalently bonded to the proten during the freeze-drying process. The ESR results on such modified proteins were indistinguishable from those obtained on the unmodified proteins, indicating that in the mixtures the transfer of unpaired spins occurs almost exclusively to suifur compounds which were not covalently bonded. The mechanisms underlying the observed migration of unpaired spins are discussed. (auth)

• Research Organization: Norsk Hydro's Inst. for Cancer Research, Montebello, Oslo
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-023161
• OSTI ID: 4712553
• Journal Information: Radiation Res., Journal Name: Radiation Res. Vol. Vol: 18
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALCOHOLS
AMINES
AMINO ACIDS
BIOLOGY AND MEDICINE
CHEMICAL REACTIONS
CRYSTALS
CYSTEAMINE
ELECTRON SPIN RESONANCE
ELECTRONS
FREE RADICALS
LABELLED COMPOUNDS
LOW TEMPERATURE
MOLECULES
ORGANIC SULFUR COMPOUNDS
PENICILLAMINE
PROTEINS
QUANTITY RATIO
RADIATION EFFECTS
RESONANCE
SPECTROSCOPY
SPIN
SULFIDES
SULFUR 35
VARIATIONS
WEIGHT