Preliminary Evidence for a Metallothionein-like Cd-binding Protein in the Kidney of the Antarctic Clam Laternula elliptica

  • Choi, Hee-Seon, J. (Polar Sciences Laboratroy, KORDI) ;
  • Ahn In-Young (Polar Sciences Laboratroy, KORDI) ;
  • Ryu Soo-Kyung (Department of Biology, Ewha Womans University) ;
  • Lee, Yong-Seok (Department of Life Sciences, Soonchunhyang University) ;
  • Lee, In-Sook (Department of Biology, Ewha Womans University) ;
  • Jeong, Kye-Heon (Department of Life Sciences, Soonchunhyang University)
  • Published : 2001.12.31

Abstract

A Cd-binding protein was identified in the renal cytosol of the Antarctic clam Laternula elliptica which naturally contains high concentrations of Cd. The Cd-binding protein showed similar characteristics of metallothionein (MT) in molecular weight (about 10-12 kDa) and low spectral absorbance at 280 nm with relatively high absorbance at 254nm. Results of immuno-histochemical staining suggested that the MT-like Cd-binding protein was mainly located in the epithelial cells of the kidney. The MT-like protein was a major ligand of cytosolic Cd as shown in the elution profiles of chromatography and may play an important role in Cd sequestration and accumulation in L. elliptica kidney. A considerable amount of Cd was also found to be associated with particulate fraction, indicating the sequestration to particulate fraction is as important as binding to the cytosolic MT-like protein in Cd accumulation in the kidney.