Occurrence of IMP-GMP 5'-nucleotidase in three fish species: a comparative study on Trachurus japonicus, Oncorhynchus masou masou and Triakis scyllium.
IMP-hydrolyzing activity, which is reactive with goose anti-pig lung IMP-GMP 5'-nucleotidase (EC.3.1.3.5) serum, was detected in extracts from various tissues of Trachurus japonicus (a marine teleost), Oncorhynchus masou masou (a freshwater teleost) and Triakis scyllium (an elasmobranch). Kinetic characteristics of the reactive enzymatic activity were similar to those of IMP-GMP 5'-nucleotidase from mammals and birds. In all species studied, the activity was highest in the liver (4-6 micromol of Pi released from IMP/min/mg of protein). The second highest activity was observed in the head portion of Oncorhynchus kidney (4 micromol of Pi released from IMP/min/mg of protein), which was twofold higher than that of its body portion. In all three species, the activity was lowest in white skeletal muscle among the tissues studied (0.1-0.3 micromol of Pi released from IMP/min/mg of protein), while the activity in red skeletal muscle was sixfold to 10-fold higher than that in white muscle.
Itoh
Roichi
R
Department of Home Economics, Tokyo Kasei Gakuin University, 2600 Aiharamachi, Machida-city, Tokyo 194-0292, Japan. roytoh@kasei-gakuin.ac.jp
Kimura
Kayoko
K
D015720:5'-Nucleotidase / Q000378:metabolism*; D000818:Animals; D005399:Fishes; D006157:Guanosine Monophosphate / Q000378:metabolism*; D007291:Inosine Monophosphate / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D013379:Substrate Specificity
D007291:Inosine Monophosphate; D006157:Guanosine Monophosphate; D015720:5'-Nucleotidase