Quantification of amino acid enantiomers in single cells by capillary electrophoresis.
An analytical method is described to quantify amino acid enantiomers in single cells. Cellular samples were derivatized with a fluorescence tagging reagent, naphthalene-2,2-dicarboxaldehyde, in a mini-volume (4 microl) prior to separation. Enantiomeric resolution was achieved by beta-cyclodextrin modified micellar electrokinetic chromatography. The separation was coupled with laser induced fluorescence detection. The method had a detection limit of 0.1 microM for aspartic acid enantiomers (1.0 microl sample solution was derivatized). Single neurons isolated from the five major ganglia of Aplysia californica were analyzed to determine the D/L enantiomeric ratios of aspartic acid, phenylalanine and leucine. D-aspartic acid was found at high levels in many neurons tested and its cellular distribution was highly heterogeneous.
Zhao
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Department of Chemistry, Jackson State University, MS 39217, USA.
LifuYM
D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry*; D000818:Animals; D001048:Aplysia / Q000737:chemistry / Q000166:cytology; D001224:Aspartic Acid / Q000032:analysis / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D009474:Neurons / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism
D000596:Amino Acids; D001224:Aspartic Acid