An improved experimental scheme to measure self-diffusion coefficients of biomolecules with an advantageous use of radiation damping

An improved nuclear magnetic resonance (NMR) experimental scheme to measure self-diffusion coefficients of biomolecules in 95% H2O using pulsed-magnet ic-field gradients is presented. The radiation damping of water, which dele teriously effects the quality of the spectra in high-field NMR, is advantag eously used in reducing the water signal. The enhancements of the new seque nce, designated BPP-SED, a novel combination of BPP-LED (bipolar-gradient-p ulse pair longitudinal eddy current delay) and SED (selective echo dephasin g) is demonstrated by measuring self-diffusion coefficients of dilute prote in samples (0.5 mM) in limited volumes (250 mu l). (C) 1999 Elsevier Scienc e B.V. All rights reserved.