Heavy metal detoxication in Mytilus kidney--an in vitro study of Cd- and Zn-binding to isolated tertiary lysosomes.
Uptake of Cd and Zn by isolated lipofuschin granules (tertiary lysosomes) has been studied. Freshly isolated granules contain Zn and approx 85% is immobilised. The granules take up ionic Cd and Zn from the surrounding medium. The metals are weakly and reversibly bound by a passive, non-concentrative adsorption process. Multiple, non metal-specific binding sites with a pKapp approximately equal to 6 and stability constant approximately equal to 5 were found. Metals can be sequestered from proteins with weakly bound metal but not from Cd-thionein. The results are discussed in relation to intracellular control of heavy metal concentrations in the cell and the pathway of Cd metabolism.
D000818:Animals; D001665:Binding Sites; D049872:Bivalvia / Q000502:physiology*; D002104:Cadmium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008658:Inactivation, Metabolic; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008247:Lysosomes / Q000378:metabolism; D011485:Protein Binding; D015032:Zinc / Q000378:metabolism*
D002104:Cadmium; D015032:Zinc