Basic Information
Abstract Number: 1000-5    
Author Name: Nobutoshi Ota Affiliation: University of Illinois at Urbana-Champaign
Session Title: Celebrating the Future of Analytical Chemistry - The ACS Division of Analytical Chemistry Graduate Fellows (ACS-ANYL)
Event Type: Organized Contributed Session
Event Title: Measuring D-Amino Acids in Aplysia Neurons via Capillary Electrophoresis with Enzymatic and Immunological Treatments
Presider(s): Edmiston, Paul Start Time: 09:35 AM ( Slot # 6 )
Date: Tuesday, March 13th, 2012 Location: 308B
Keywords: Amino Acids, Capillary Electrophoresis, Chiral Separations, Neurochemistry

Replogle, LeeUniversity of Illinois at Urbana-Champaign
Rubakhin, StanislavUniversity of Illinois at Urbana-Champaign
Sweedler, Jonathan VUniversity of Illinois
Wang, LipingUniversity of Illinois at Urbana-Champaign

Abstract Content
Several amino acids in the central nervous system (CNS) work as neurotransmitters and neuromodulators that are critical for cell to cell signaling and neuronal network function. Besides L-amino acids, there are several D-amino acids found in the neurons of animals but the presence and function of these D-amino acids are not well understood, partly because of analytical challenges in their measurement. The chemical complexity, great excess of L-amino acids, and small volume samples contribute to these challenges. Here we use several capillary electrophoresis (CE) approaches to quantify D-glutamate (D-Glu) and D-aspartate (D-Asp) and confirm our identifications of these D-amino acids using both enzyme and antibody treatments. Our samples (here the Aplysia californica CNS) are treated separately with D-aspartate oxidase, an enzyme that oxidizes D-Glu and D-Asp, with antibodies for D-Glu and D-Asp, or with saline. Next, the treated samples are derivatized with amine-reactive fluorogenic reagent, naphthalene-2,3-dicarboxaldehyde (NDA), followed by analysis via CE with laser-induced fluorescence (LIF). CE-LIF is well suited to these measurements because it requires small sample volumes and its high sensitivity. Chiral separation of derivatized amino acids is achieved with chiral selector, alpha-cyclodextrin. Our results clearly demonstrate the presence of D-Glu and D-Asp in Aplysia CNS, and the enzyme and antibody treatments confirm these assignments. We are now examining how D-Glu and D-Asp change in Aplysia neurons in response to chemical and electrical stimulations to correlate electrophysiological activity of the neurons and release of the D-amino acids.