A cadmium-binding protein in rat liver identified as ornithine carbamoyltransferase.
A cadmium-binding protein of Mr about 40,000 (40K Cd-BPa) was detected in rat liver by Western blotting [Aoki, Kunimoto, Shibata & Suzuki (1986) Anal. Biochem. 157, 117-122]. It was characterized and identified as ornithine carbamoyltransferase (OCTase, EC 2.1.3.3) on the basis of coincidence of their physicochemical and enzymological features. The amino acid sequence of the N-terminal and those of three tryptic digests in 40K Cd-BPa were identical with those of OCTase. The Mr values of the denatured and native forms of 40K Cd-BPa (39,000 and 110,000 respectively) were the same as those of OCTase. 40K Cd-BPa showed, as OCTase activity, a specific activity of 230 mumol/min per mg of protein and Km of 0.6 mM for ornithine, this value also being essentially the same as that for OCTase. A rabbit antibody against OCTase reacted with 40K Cd-BPa. The native form of 40K Cd-BPa bound to 0.8 molar equiv, of cadmium, with a dissociation constant of 7.6 x 10(-6) M.
Aoki
Y
Y
National Institute for Environmental Studies, Ibaraki, Japan.
Sunaga
H
H
Suzuki
K T
KT
D000595:Amino Acid Sequence; D000818:Animals; D002104:Cadmium / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000201:enzymology*; D008297:Male; D008668:Metallothionein / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D009954:Ornithine Carbamoyltransferase / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
C004203:cadmium-binding protein; D002104:Cadmium; D008668:Metallothionein; D009954:Ornithine Carbamoyltransferase