title: Insights into enzyme function from studies on mutants of dihydrofolate reductase.
abstract: Kinetic analysis and protein mutagenesis allow the importance of individual amino acids in ligand binding and catalysis to be assessed. A kinetic analysis has shown that the reaction catalyzed by dihydrofolate reductase is optimized with respect to product flux, which in turn is predetermined by the active-site hydrophobic surface. Protein mutagenesis has revealed that specific hydrophobic residues contribute 2 to 5 kilocalories per mole to ligand binding and catalysis. The extent to which perturbations within this active-site ensemble may affect catalysis is discussed in terms of the constraints imposed by the energy surface for the reaction.
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D007780:Lacticaseibacillus casei / Q000201:enzymology; D009154:Mutation; D013329:Structure-Activity Relationship; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D013762:Tetrahydrofolate Dehydrogenase