Chapter 3 - Preperation of 2H, 13C and 15N Isotopically-enriched Proteins for NMR Spectroscopic Investigations

Abstract

Developments in the field of biotechnology have made it easy and economical to introduce 2H, 13C, and 15N isotopic labels into proteins either uniformly or selectively. At the same time, an explosion in the number of nuclear magnetic resonance (NMR) experiments that can exploit the isotopic labeling to obtain resonance assignments and to extract structural, dynamic, and biological information has occurred. Varieties of procedures are developed to isotopically-enrich proteins, most of which involve the use of an organism that expresses or over-expresses the protein of interest. This chapter presents the general details of each and discusses their advantages and disadvantages. Isotopic enrichment, using photosynthetic bacteria or algae, bacteria, yeast, and mammalian expression sections, is considered, and several methods of enrichment that do not use protein expression vehicles. A brief overview of NMR experiments that exploit isotopic enrichment is also presented.