Purification and partial characterization of a cadmium-binding protein from the liver of rainbow trout (Onchorynchus mykiss).
This study describes the isolation and partial characterization of a low molecular weight (approximately 14 kDa), cadmium-binding protein from rainbow trout (Onchorynchus mykiss) liver. Rainbow trout were injected intraperitoneally with 3.5 mg/kg cadmium chloride (total body dose) twice weekly for 3 wk. Livers were removed and a cadmium-binding protein was isolated. Monoclonal antibodies produced against this protein were used in the affinity purification process. Amino acid analysis showed the protein contained 3.8 mol% cysteine, 3.5 mol% phenylalanine, 2.2 mol% tyrosine and 1.9 mol% histidine. The low cysteine content suggests that it was distinct from metallothionein. The monoclonal antibodies were also used to identify the protein in liver homogenates from both cadmium-exposed and control fish and in the testes of cadmium-exposed mice lacking the gene for both metallothionein-1 and metallothionein-II. The compound identified in this study represents a non-metallothionein cadmium-binding protein that appears to be highly conserved.
Mullins
J E
JE
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown.
Fredrickson
R A
RA
Fuentealba
I C
IC
Markham
R J
RJ
D000818:Animals; D000911:Antibodies, Monoclonal; D002104:Cadmium / Q000633:toxicity; D008099:Liver / Q000737:chemistry; D008668:Metallothionein / Q000302:isolation & purification*; D051379:Mice; D017686:Oncorhynchus mykiss / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity
D000911:Antibodies, Monoclonal; D014874:Water Pollutants, Chemical; C004203:cadmium-binding protein; D002104:Cadmium; D008668:Metallothionein