Cholinesterase Structure: Identification of Mechanisms and Residues Involved in Organophosphate Inhibition and Enzyme Reactivation
Abstract
Studies on the structure of acetylcholinesterase (AChE) as a target for organophosphate toxicity continue and have resulted in several leads of significance. First, we have completed the first phase of studies of the structural determinants on the enzyme responsible for inactivation and oxime reactivation. The oxime reactivation studies reveal mutations whereby reactivation can be accelerated some 100-fold, and the combination oxime-mutant AChE shows promise as a prophylactic agent or antidote. Second, through cysteine-substitution mutagenesis and labeling, we have developed steady-state and anisotrophy decay fluorescence methods to examine segmental motion in the protein. This has yielded valuable information on the flexibility of the active center gorge, and the practical outcome of a potentially high sensitivity detection method for organophosphate exposure using the enzyme target as a detector. Third, we have developed an analytical means of measuring organophosphate exposure by MALDI-TOF mass spectrometry that actually measures the product rather than drawing inferences from inhibition of activity. Lastly, several other studies related to our overall objectives are underway. The first is the production of gene knockouts for all of the cholinesterase splice variants.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2003
- Accession Number
- ADA417075
Entities
People
- Palmer W. Taylor
Organizations
- University of California, San Diego