Radiolysis of metallothionein in deaerated and oxygen-saturated solutions.
Gamma radiolysis of metallothionein (MT) in phosphate-buffered solutions at pH 8.0 leads to the formation of intra- and intermolecular disulfide bridges as well as the release of chelated metal ions. When MT solutions deaerated with N2 or saturated with N2O were irradiated, G values for RS- loss as determined by Ellman's reagent were 4.2 and 7.0, respectively, whereas those for dimerization were only 0.32 and 0.67. A short chain reaction existed in the decrease in RS- when radiolysis was performed in O2-saturated solutions. The rate constants for reactions of MTs with OH radical and H2O2 were measured to be about 10(12) and 100 M-1 s-1, respectively. A mechanism for the radiolysis of MT-1 is proposed.
Fang
X
X
Department of Technical Physics, Peking University, Beijing, People's Republic of China.
Wu
J
J
Wei
G
G
D000818:Animals; D005295:Ferrocyanides / Q000737:chemistry; D005720:Gamma Rays; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000737:chemistry; D008668:Metallothionein / Q000737:chemistry / Q000528:radiation effects*; D010100:Oxygen / Q000737:chemistry*; D011817:Rabbits; D012996:Solutions
D005295:Ferrocyanides; D012996:Solutions; D008668:Metallothionein; C020354:hexacyanoferrate II; D010100:Oxygen