A direct NMR method for the measurement of competitive kinetic isotope effects

作者:Chan Jefferson*; Lewis Andrew R; Gilbert Michel; Karwaski Marie France; Bennet Andrew J
来源:Nature Chemical Biology, 2010, 6(6): 405-407.
DOI:10.1038/nchembio.352

摘要

We present a technique that uses (13)C NMR spectroscopy to measure kinetic isotope effects on the second-order rate constant (k(cat)/K(m)) for enzyme-catalyzed reactions. Using only milligram quantities of isotopically labeled substrates, precise competitive KIEs can be determined while following the ongoing reaction directly in a NMR spectrometer. Our results for the Vibrio cholerae sialidase-catalyzed hydrolysis of natural substrate analogs support a concerted enzymatic transition state for these reactions.

  • 出版日期2010-6