Metal-induced dimerization of Cd7-metallothionein. Role of anions
Palumaa, P.; Vaher, M.
Annals of Clinical and Laboratory Science 26(3): 264-268
1996
ISSN/ISBN: 0091-7370 PMID: 8726219 Document Number: 464673
Inorganic phosphate participates in the nonoxidative Cd-dependent dimerization of Cd-7-metallothionein (Cd-7-MT) and is bound to the MT dimers. In order to obtain insight into the specificity of phosphate-MT interaction, an investigation has been made on the effect of a series of oxyanions and organic phosphates on Cd-induced dimerization of Cd-7-MT. It has been demonstrated that from the oxyanions studied, only arsenate and tungstate can promote Cd-induced dimerization of Cd-7-MT. Effect of arsenate is quantitatively similar to that of phosphate and appears at submillimolar concentrations, whereas tungstate promotes dimerization of MT at higher, millimolar concentrations. A number of other oxyanions, ie, molybdate, vanadate, and selenate as well as organic phosphates (phenyl phosphate, serine O-phosphate, D-ribose 5-phosphate, L-glycerol 3-phosphate, D-fructose 6-phosphate, D-glucose 6-phosphate, adenosine monophosphate (AMP), cyclic adenosine monophosphate (cAMP), nicotinamide-adenine-dinucleotide (NADP), pyridoxal 5-phosphate) had no influence on Cd-induced dimerization of MT. Results obtained strongly indicate a highly specific role of inorganic phosphate in Cd-induced dimerization of Cd-7-MT.