Tl super(+) Showed Negligible Interaction with Inner Membrane Sulfhydryl Groups of Rat Liver Mitochondria, but Formed Complexes with Matrix Proteins

• Published in: Journal of biochemical and molecular toxicology 2014-04, Vol.28 (4), p.149-156
• Main Authors: Korotkov, Sergey M, Brailovskaya, Irina V, Kormilitsyn, Boris N, Furaev, Viktor V
• Format: Article
• Language: English
• ISSN: 1095-6670; 1099-0461
• DOI: 10.1002/jbt.21547

The effects of Tl super(+) on protein sulfhydryl (SH) groups, swelling, and respiration of rat liver mitochondria (RLM) were studied in a medium containing TlNO sub(3) and sucrose, or TlNO sub(3) and KNO sub(3) as well as glutamate plus malate, or succinate plus rotenone. Detected with Ellman's reagent, an increase in the content of the SH groups was found in the inner membrane fraction, and a simultaneous decline was found in the content of the matrix-soluble fraction for RLM, incubated and frozen in 25-75 mM TlNO sub(3). This increase was greater in the medium containing KNO sub(3) regardless of the presence of Ca super(2+). It was eliminated completely for RLM injected in the medium containing TlNO sub(3) and then washed and frozen in the medium containing KNO sub(3). Calcium-loaded RLM showed increased swelling and decreased respiration. These results suggest that a ligand interaction of Tl super(+) with protein SH groups, regardless of the presence of calcium, may underlie the mechanism of thallium toxicity.