Properties of cadmium-binding proteins in rat testes. Characteristics unlike metallothionein.
Since the exposure of rats to cadmium causes zinc to accumulate in metallothionein in liver and kidney but not in a similar protein in the testes, the properties of the low-Mr cadmium-binding proteins were investigated in rat testes. Weanling rats that had been given dietary cadmium for 6 weeks were injected with 109CdCl2 and subsequently killed, and the 109Cd-labelled low-Mr proteins from testes were purified. The pooled low-Mr cadmium-containing fractions from the gel-filtration (Sephadex G-75) columns were eluted through DEAE-Sephacel columns, yielding two peaks. Each of the individual peaks from this Sephacel column was further purified by rechromatography on DEAE-Sephacel and on Bio-Gel P-10 columns. Amino acid analysis of the two purified proteins revealed a low cysteine (about 3%) content, with aspartate, glutamate and glycine as the predominant amino acids. Thus these low-Mr cadmium-binding proteins induced by cadmium in rat testes do not appear to be metallothionein.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002104:Cadmium / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000378:metabolism; D008297:Male; D008668:Metallothionein / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D013737:Testis / Q000378:metabolism*
D000596:Amino Acids; C004203:cadmium-binding protein; D002104:Cadmium; D008668:Metallothionein