Free and bound pyruvate kinase from fish brain: properties and redistribution after hypoxia.
In the brain of European red mullet, 14.5 +/- 1.9% of pyruvate kinase activity is connected with the particulate fraction. This enzyme form disappears after 90 min hypoxia of fish. pH-Dependences of the free and bound pyruvate kinase forms are similar. Km for phosphoenolpyruvate and adenosinediphosphate of the free enzyme was 2-3-fold higher than that of the bound one. When heated at 45 degrees C, free pyruvate kinase gets inactivated, while the bound form is, in succession, activated and stabilized. The possible role of reversible phosphorylation in the regulation of properties and distribution of pyruvate kinase in the cell is discussed.
Lushchak
V I
VI
Karadag Branch of Southern Seas Biology Institute, Feodosia, Crimea, Ukraine.
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology*; D004789:Enzyme Activation; D005399:Fishes / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000378:metabolism; D007700:Kinetics; D011770:Pyruvate Kinase / Q000378:metabolism*
D011770:Pyruvate Kinase