Quantification of D/L-aspartic acids in Aplysia californica central nervous system by beta-cyclodextrin modified micellar electrokinetic chromatography.
In presence of an organic modifier (e.g. methanol), separation of amino acid enantiomers tagged with naphthalene-2,3-dicarboxaldehyde by beta-cyclodextrin modified micellar electrokinetic chromatography was dramatically improved. Coupled with laser-induced fluorescence detection, the method was well suited for analysis of D/L-amino acid enantiomers present in mass/volume-limited biological samples such as cell clusters. The five major ganglia dissected from the central nervous system of Aplysia californica, a widely used neuronal model, were analyzed to determine D- and L-aspartic acid enantiomers both free and bound in proteins/tissue matrix. The analyses revealed high levels of free D-aspartic acid ranging from 0.13 to 0.82 micromol/g wet tissue (or 6.0-21.2% of the total free aspartic acid) in all of the five ganglia. However, no D-aspartic acid was detected bound in protein/tissue matrix. The content of free D-aspartic acid in the liver tissue was also found below the detection limit of the method, which was 1 x 10(-8) M.
Zhao
S
S
Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.
Liu
Y M
YM
D000818:Animals; D001048:Aplysia / Q000737:chemistry*; D001224:Aspartic Acid / Q000032:analysis* / Q000737:chemistry; D002490:Central Nervous System / Q000737:chemistry*; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D003505:Cyclodextrins / Q000737:chemistry*; D013237:Stereoisomerism; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D001224:Aspartic Acid; C031215:betadex