Involvement of the conserved histidine-188 residue in the L-lactate dehydrogenase from Thermus caldophilus GK24 in allosteric regulation by fructose 1,6-bisphosphate.
The conserved histidine-188 residue of the L-lactate dehydrogenase of Thermus caldophilus GK 24, which is allosterically activated by fructose 1,6-bisphosphate, has been exchanged to phenylalanine by site-specific mutagenesis. In the mutant enzyme the strong stimulatory effect of fructose 1,6-bisphosphate is abolished. The analysis of the pH dependence of the activity indicates that the positive charge of the conserved His-188 residue is important for the interaction of the enzyme with the allosteric effector.
Schroeder
G
G
Department of Agricultural Chemistry, University of Tokyo, Japan.
Matsuzawa
H
H
Ohta
T
T
D001665:Binding Sites; D005635:Fructosediphosphates / Q000378:metabolism*; D006598:Hexosediphosphates / Q000378:metabolism*; D006639:Histidine; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D010649:Phenylalanine; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid; D013824:Thermus / Q000201:enzymology*
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D011773:Pyruvates; D010649:Phenylalanine; D006639:Histidine; D019289:Pyruvic Acid; D007770:L-Lactate Dehydrogenase; C029063:fructose-1,6-diphosphate