Abstract
Two-dimensional (2 D) nuclear magnetic resonance (NMR) spectroscopy is a useful tool for the structure elucidation of proteins with a molecular weight of up to ca. 10 kDa. This molecular size limitation is caused by resonance overlap in 2 D NMR spectra and the low sensitivity due to large linewidth associated with the increased size of proteins. Recent progress of recombinant DNA technology allowed one to obtain 13C- and/or 15N-labelled proteins in large quantities. Development of multi-dimensional NMR technique using such labelled proteins has made it possible to determine solution structures of larger proteins up to ca. 30 kDa by increasing spectral resolution and utilizing large one-bond J couplings for transfer magnetization. This novel NMR technique may open great possibilities for us to understand important problems in the fields of protein chemistry and protein engineering.
