Effect of some metal ions on blood and liver delta-aminolevulinate dehydratase of Pimelodus maculatus (Pisces, Pimelodidae).
1. delta-ALA-D from Pimelodus maculatus was inhibited in vitro by Cd2+ greater than Pb2+ greater than Hg2+ greater than Cu2+ greater than Zn2+ in blood and by Pb2+ greater than Cd2+ greater than Hg2+ greater than Cu2+ = Zn2+ in the liver. 2. Kinetic analysis of the inhibition by the metal ions showed that Cd2+ and Hg2+ act as non-competitive inhibitors on both sources. 3. Pb2+ showed a mixed type of inhibition in blood and a non-competitive type in the liver. 4. Zn2+ acted as a competitive or mixed inhibitor, on both sources, depending on concentration.
Rodrigues
A L
AL
Departamento de Bioquímica e Centro de Ecologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
Bellinaso
M L
ML
Dick
T
T
D000818:Animals; D001667:Binding, Competitive; D002104:Cadmium / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D005399:Fishes / Q000378:metabolism*; D007700:Kinetics; D007854:Lead / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D008628:Mercury / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors* / Q000097:blood; D015032:Zinc / Q000494:pharmacology
D008670:Metals; D002104:Cadmium; D007854:Lead; D003300:Copper; D000623:Porphobilinogen Synthase; D008628:Mercury; D015032:Zinc