Characterizing Neuropeptides with Chiral Modifications

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Professor Jonathan Sweedler of the U of Ill Urbana-Champaign is supported by the Analytical and Surface Chemistry Program to analyze a chiral post-translational modification in neuropeptides, namely, an L to D isomerization thought to activate the peptide biologically. The biological system under study is the single neuron of Aplysia californica. There are three proposed approaches: instrumental, enzymatic and immunological. In the first, chiral separation methods will be used to try to resolve diastereomeric peptides that differ by D/L isomerization of one of the amino acids. Secondly, N-terminal peptidases that cleave only L-amino acids will be used followed by analysis of fragments by matrix-assisted laser desorption ionization mass spectrometry (MALDI). A third approach is to attempt to grow antibodies to peptides containing D-amino acids. The goal is to discover new D-amino acid containing peptides that function neurologically. Students in this laboratory are trained in analytical chemistry and neurobiology. Signaling in the brain and nervous system is accomplished to a large extent by a vast number of peptides, many as yet undiscovered. The well studied Aplysia snail system gives researchers one model system that a great deal is already known about. Success of this project will allow a better understanding of peptides in neurochemistry, as well as in neurological diseases such as Alzheimer's, and will also contribute to advances in analytical methods for other questions in biology and pharmacy.