New Inhibitors of the Peripheral Site in Acetylcholinesterase that Specifically Block Organophosphorylation
Abstract
Examination of the enzyme structure for acetylcholinesterase (AChE) reveals two sites of ligand interaction: The peripheral site (P-site) located at the entrance of the gorge, and the acylation site (A-site) at the base of the gorge. Our goal is to develop high affinity cyclic peptide ligands specific for the P-site that would block the access of organophosphate agents while allowing the passage of acetylcholine to the A-site for use by personnel at risk for nerve gas exposure. Our immediate strategy involves the covalent tethering of cyclic inhibitors via a methanethiosulfonate (MTS) linkage to a cysteine on the AChE mutant, H287C. We are using a combinatorial approach to identify tethered cyclic peptides with high affinity for the P-sfte. The modified AChEs linked to candidate peptides that inhibit P-site access are selected by affinity chromatography. We are developing mass spectrometry techniques to determine the peptide structure of these candidates. These include release of the cyclic peptide by reduction with DTT and peptide sequencing by 1 dimensional liquid chromatographic ESI ion-trap mass spectrometry. This method should provide the peptide amino acid sequence through its MSn capabilities, which allow for peptide fragment analysis through several stages of consecutive collisionally activated decomposition (CAD) mass spectra.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2004
- Accession Number
- ADA424552
Entities
People
- Terrone L. Rosenberry
Organizations
- Mayo Clinic