The Study of the Metabolism of 13C Labeled Substrates by 13C NMR Spectroscopy of Intact Cells, Tissues, and Organs

Abstract

Carbon-13 nuclear magnetic resonance (nmr) spectroscopy, in conjunction with carbon-13 labeling, has become an important analytical technique for the study of biological systems and biologically important molecules. The growing list of its well established applications to isolatedmoleculesinsolution includes the investigation of: metabolic pathways; the microenvironments of ligands bound to proteins; the architecture and dynamics of macromolecules; the structures of coenzymes and other natural products; and the mechanisms of reactions. Recently interest has been reawakened in the use of the technique for the study of metabolic pathways and structural components in intact organelles, cells, and tissues. The promise and problems in the use of 13C nmr spectroscopy and 13C labeling in such investigations can be illustrated by the results of some early work on suspensions of the yeast, Candida utilis (1, 2). Reproduced in Figure 1 is a set of 13C nmr spectra of a thick suspension of