Identification of Spinal Neuropeptides in the Rat through Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry
Through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), over 440 neuropeptides have been identified in the brain (Hummon, Amare, & Sweedler, 2006). However, few biologically-active peptides have been identified in the spine and, thus, research on the rat spinal cord was conducted. To understand the brain and its means of communication, the study of neurons and their transported chemical messengers was essential. Neurotransmitters are chemical messengers. Depending on the surrounding conditions, neuropeptides, a subclass of neurotransmitters, can act as neurotransmitters, neuromodulators, or neurohormones (Strand, 1999). In order to detect the peptides, a sensitive instrument was needed. MALDI-TOF MS proved useful due to its sensitivity to detect ions, ability to provide spatial information of peptides, and contribution to de novo sequencing through fragmentation of neuropeptides. The procedure entailed extracting and homogenizing peptides with acidified acetone, mixing the spinal neuropeptides with a matrix-assisted medium, running the target plate through MALDI, and determining amino acid sequences based on the fragmentation spectra. The presence of 40+ spinal peptides was detected through MALDI, though the indication of biologically-active peptides was unclear based on various output and the resulting sequences. The study of the spinal cord and how it functions in conjunction with the brain to influence propagation of neuronal signals and cell-cell communication is significant - even if the peptides have been previously identified in the brain.
School:
Lawrence University
Department:
Interdisciplinary Chemistry and Biology
Research Advisor:
Jonathan Sweedler
Department of Research Advisor:
Analytical Chemistry
Year of Publication:
2006