The use of deoxyfluoro-D-galactopyranoses in a study of yeast galactokinase specificity.
1. 2-Deoxy-2-fluoro-d-galactose, 3-deoxy-3-fluoro-d-galactose, 4-deoxy-4-fluoro-d-galactose, 6-deoxy-6-fluoro-d-galactose and 2-deoxy-d-lyxo-hexose are substrates for yeast galactokinase. 2. The variation in K(m) values for the d-hexose derivatives was not associated with a variation in the value of K(m) for MgATP(2-) indicating that the binding of MgATP(2-) is not modified by the binding of the sugar substrate. 3. Donated H bonds from OH-3, OH-4 and OH-6 and an accepted H bond to OH-2 of the d-hexose are important for the binding of the sugar substrate to galactokinase. 4. Yeast galactokinase exhibits similar kinetics to the galactokinase from Escherichia coli and operates by a similar random sequential mechanism. 5. 4-Deoxy-4-fluoro-d-glucose was neither a substrate for nor an inhibitor of yeast galactokinase.
D000255:Adenosine Triphosphate; D001665:Binding Sites; D002854:Chromatography, Paper; D003201:Computers; D004926:Escherichia coli; D005461:Fluorine; D005643:Fucose; D005690:Galactose; D007700:Kinetics; D008274:Magnesium; D010770:Phosphotransferases; D013053:Spectrophotometry; D015003:Yeasts / Q000201:enzymology*
D005461:Fluorine; D005643:Fucose; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D008274:Magnesium; D005690:Galactose