title: Uses of isotope effects in the study of enzymes.
abstract: There have been few recent additions to the technical methods employed in the study of isotope effects, notable exceptions being the use of high pressure as an experimental variable and the measurement of heavy-atom isotope effects on maximal velocities using continuous-flow techniques. Most of the innovations are in the realm of new experimental designs that allow the asking of new questions. These designs include the use of isotope effects to: determine kinetic mechanisms, distinguish between changes in enzymatic activity and loss of active enzyme, distinguish between reactant-state origins and transition-state origins and quantify hydrogen tunneling, separate and quantify multiple origins of solvent isotope effects, distinguish between concerted and stepwise chemical mechanisms, characterize bond order changes in ligand binding, distinguish different pathways of inhibitor binding, and estimate intrinsic isotope effects.
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, Madison, Wisconsin 53706, USA. dbnorthrop@pharmacy.wisc.edu
authors.forename: D B
authors.initials: DB
authors.lastname: Northrop
mesh_terms: D001671:Biochemistry / Q000379:methods*; D004798:Enzymes / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D007554:Isotopes; D007700:Kinetics; D008024:Ligands; D008956:Models, Chemical; D011485:Protein Binding
chemical_list: D004798:Enzymes; D007554:Isotopes; D008024:Ligands; D006859:Hydrogen