12] Pulse Fourier-transform NMR spectroscopy with applications to redox proteins

Abstract

This chapter discusses the theoretical basis and methodological details for carrying out Fourier-transform (FT) NMR experiments in biochemical redox systems. In the pulse FT method a 90° pulse reorients the total magnetization of the sample into the transverse plane; moreover, information on the entire spectrum can be obtained in a time of the order of 3T2* where T2* is the apparent lifetime of the transverse magnetization, resulting in a marked improvement in sensitivity. The data thus obtained as a time response are not in an easily interpretable form, but it is now well known that simple Fourier transformation leads to the true slow-passage NMR spectrum. When long pulses are used, selected regions of the spectrum can be studied. However, the Fourier-transform method requires a computer. After considering the basic Fourier-transform instrument and the preparation of samples, the general experimental conditions for Fourier-transform NMR and special methods especially useful in redox systems are considered in the chapter.