Improved three-dimensional1H-13C-1H correlation spectroscopy of a13C-labeled protein using constant-time evolution

Abstract

An improved version of the three-dimensional HCCH-COSY NMR experiment is described that correlates the resonances of geminal and vicinal proton pairs with the chemical shift of the13C nucleus attached to one of the protons. The experiment uses constant-time evolution of transverse13C magnetization which optimizes transfer of magnetization and thus improves the sensitivity of the experiment over the original scheme. The experiment is demonstrated for calmodulin complexed with a 26-residue peptide comprising the binding site of skeletal muscle myosin light chain kinase. © 1991 ESCOM Science Publishers B.V.