| Abstract: | Lyophilized whole cells of Aerococcus viridans (Gaffkya homari) grown on a synthetic medium containing D-2-13C, 15N]Ala, or containing both L-1-13C]Lys and D-15N]Ala, have been examined by double cross-polarization magic-angle spinning 13C and 15N nuclear magnetic resonance. Results from the double-labeled alanine experiment confirm the absence of metabolic scrambling of alanine by A. viridans. Results from the combined single-label experiment can be used to count directly the number of adjacent L-Lys and D-Ala units in peptide chains of cell-wall peptidoglycan. This count leads to the conclusion that there are no terminal D-Ala or D-Ala-D-Ala units in uncross-linked chains of the peptidoglycan of A. viridans. |
