Measurement of Kinetic Isotope Effects by Continuously Monitoring Isotopologue Ratios Using NMR Spectroscopy

Abstract

Nuclear magnetic spectroscopic (NMR) methods are discussed for the measurement of heavy atom (¹³C, ¹⁸O, ¹⁵N) and secondary deuterium kinetic isotope effects. The discussion focuses primarily on the NMR methods that enable the measurement of quantitative spectra and not on methods to make labeled substrates. Two main techniques are considered: single-point determinations on natural abundance material and the continuous monitoring of isotopically enriched materials. The second method is described in more detail, and we include a discussion of the current state of instrumentation and computer programs for data acquisition and analysis.

Keywords: 1D and 2D NMR; Competitive KIE; Glycosidase; Mechanism; Quantitative NMR.