title: Solid-state 13C and 15N nuclear magnetic resonance studies of alanine metabolism in Aerococcus viridans (Gaffkya homari).
abstract: Transport and metabolism of D- and L-alanine by Aerococcus viridans (Gaffkya homari) have been studied using cross-polarization magic-angle spinning 13C and 15N NMR spectroscopy of lyophilized whole cells, isolated cell walls, and crude extracts. For equimolar concentrations in the growth medium, about 10 times more D-alanine than L-alanine is transported into the cells. Examination of cells labeled with D-[13C]alanine and L-[epsilon-15N]lysine by double cross-polarization magic-angle spinning 15N NMR indicates that only about 20% of the D-alanine present in cell-wall peptidoglycan comes directly from the growth medium. The rest is produced by de novo synthesis. Most of the labeled D-alanine is found within peptidoglycan precursors or inverted to L-alanyl residues of soluble proteins.
mesh_terms: D000409:Alanine / Q000378:metabolism*; D002247:Carbon Isotopes; D007536:Isomerism; D007930:Leucine / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009587:Nitrogen Isotopes; D010457:Peptidoglycan / Q000096:biosynthesis; D013289:Streptococcaceae / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010457:Peptidoglycan; D007930:Leucine; D000409:Alanine