Identification of a cadmium-binding protein from a cadmium-resistant variant of human lymphoblastoid cells (WI-L2).
Cadmium-binding protein synthesis and induction by cadmium chloride were studied in the human lymphoblastoid cell line WI-L2. Lymphoblasts were adapted to growth in 5 microM cadmium chloride (Cdr) and these cells were 2.5-fold more resistant to cadmium than the parental line. There was no difference in the cellular protein profile between the parental line and lymphoblasts grown for a short period, less than 10 days, in cadmium chloride as measured by [35S]cysteine labelling and SDS-polyacrylamide gel electrophoresis. A basal level of cadmium binding protein was apparent, however, by gel filtration. The Cdr lymphoblasts were found to synthesize a substantial amount of cadmium-binding protein, approximately 25-fold more than the parental line. The cadmium-binding protein has the following properties which are consistent with its being a metallothionein: (1) [35S]Cysteine-labelled protein eluted at a Ve/Vo = 2.1 on a Sephadex G-75 column; (2) the molecular weight was estimated as 11 kDa on 7-17% SDS polyacrylamide gels; (3) the protein was heat-stable; (4) the unlabelled protein bound 109Cd2+.
D002104:Cadmium / Q000378:metabolism* / Q000494:pharmacology; D019256:Cadmium Chloride; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004351:Drug Resistance; D014644:Genetic Variation; D006801:Humans; D007945:Leukemia, Lymphoid; D008214:Lymphocytes; D008668:Metallothionein / Q000378:metabolism*
C004203:cadmium-binding protein; D002104:Cadmium; D008668:Metallothionein; D019256:Cadmium Chloride