Purification and characterization of fructose-1,6-bisphosphatase from bovine brain.
Fructose-1,6-bisphosphatase from bovine brain tissue has been purified to near homogeneity. This enzyme is similar to other mammalian fructose-1,6-bisphosphatases in many respects, and its properties are distinctly different from those reported for the enzyme from rat brain [A. L. Majumder and F. Eisenberg (1977) Proc. Natl. Acad. Sci. USA 74, 3222-3225; S. Chattoraj and A. L. Majumder (1986) Biochem. Biophys. Res. Commun. 139, 571-580]. The bovine enzyme (sp act 4, pH ratio (7.5/9.6) = 3.6) has a pH optimum of 7.5. The Km is 2 microM. Divalent metal ion is required for activity, and Vmax is obtained at either 4 mM Mg2+ or 0.3 mM Mn2+. Fructose 2,6-bisphosphate is a competitive inhibitor (Ki = 0.07 microM), and AMP a noncompetitive inhibitor (kis = 24 microM, Kii = 10 microM) of bovine brain fructose-1,6-bisphosphatase. The enzyme activity is enhanced by small amounts of EDTA relative to metal, and AMP inhibits fructose-1,6-bisphosphatase in either the presence or absence of the metal chelator; however, AMP is more effective in the absence of EDTA.
Liu
F
F
Department of Biochemistry and Biophysics, Iowa State University of Science and Technology, Ames 50011.
Fromm
H J
HJ
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000201:enzymology*; D002413:Cations, Divalent; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology; D006597:Fructose-Bisphosphatase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D005635:Fructosediphosphates / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D051381:Rats
D002413:Cations, Divalent; D005635:Fructosediphosphates; D000249:Adenosine Monophosphate; D008345:Manganese; C027652:fructose 2,6-diphosphate; D004492:Edetic Acid; D006597:Fructose-Bisphosphatase; D008274:Magnesium