DIRECT OBSERVATION OF CELL-WALL GLUCANS IN WHOLE CELLS OF SACCHAROMYCES-CEREVISIAE BY MAGIC-ANGLE-SPINNING C-13-NMR

Intact cells of Saccharomyces cerevisiae were examined as an aqueous paste by C-13-nmr spectroscopy with direct polarization and magic-angle spinning. The spectra obtained were highly resolved, showing numerous resonances in the 60-105 ppm range that were assigned to carbons of a liquid-like domain of the cell wall glucan. Assignments were confirmed by running the spectrum of S. cerevisiae in which the cell wall glucans were labeled with [C-13] by feeding the cell [C-13] galactose. The spectra indicate that the glucan in the cell wall of intact S. cerevisiae assumes a helical conformation and suggest that strain 17A fed with galactose preferentially incorporates the resulting glucose into beta(1 --> 3)-linkages. (C) 1994 John Wiley & Sons, Inc.