Metallothionein-like protein in the least killifish Heterandria formosa and its role in cadmium resistance.
Metallothioneins (MTs) are a class of low molecular weight, cysteine-rich, metal-binding proteins ubiquitous in animals. They function in metal regulation and detoxification. An MT-like protein was separated by gel-permeation high-performance liquid chromatography (HPLC) in the least killifish Heterandria formosa exposed to 6 mg/L of Cd for 26 h. Western blot analysis showed that this protein cross-reacted with a cod-MT antibody. We quantified MT-like protein levels by the Cd-hemoglobin saturation assay in fish from two Cd-resistant and two control laboratory populations. Fish from the resistant populations had higher MT-like protein levels than those from the control populations; this difference was found for basal levels and for levels after 26 h of exposure to Cd. Our results suggest that the MT-like protein detoxified Cd in the least killifish and accounted for at least part of the increased resistance in the Cd-resistant laboratory populations.
Xie
Lingtian
L
Department of Biology, University of Louisiana at Lafayette, P. O. Box 42451, Lafayette, Louisiana 70504, USA.
Klerks
Paul L
PL
D000818:Animals; D015153:Blotting, Western; D002104:Cadmium / Q000494:pharmacology* / Q000633:toxicity*; D002851:Chromatography, High Pressure Liquid; D004351:Drug Resistance; D005399:Fishes / Q000502:physiology*; D008668:Metallothionein / Q000032:analysis* / Q000494:pharmacology*; D014873:Water Pollutants / Q000494:pharmacology* / Q000633:toxicity*
D014873:Water Pollutants; D002104:Cadmium; D008668:Metallothionein