Engineering Dynamic Surface Peptide Networks on ButyrylcholinesteraseG117H for Enhanced Organophosphosphorus Anticholinesterase Catalysis
| Autor: | Krishna Bhattarai, Pratul K. Agarwal, Kirstin Hester, Haobo Jiang, Carey Pope |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
0303 health sciences biology Paraoxon Chemistry Stereochemistry Kinetics Mutant Active site Peptide General Medicine 010501 environmental sciences Toxicology 01 natural sciences 03 medical and health sciences Enzyme biology.protein medicine Enzyme Reactivation Butyrylcholinesterase 030304 developmental biology 0105 earth and related environmental sciences medicine.drug |
| Zdroj: | Chemical Research in Toxicology. 32:1801-1810 |
| ISSN: | 1520-5010 0893-228X |
| Popis: | The single residue mutation of butyrylcholinesterase (BChEG117H) hydrolyzes a number of organophosphosphorus (OP) anticholinesterases. Whereas other BChE active site/proximal mutations have been investigated, none are sufficiently active to be prophylactically useful. In a fundamentally different computer simulations driven strategy, we identified a surface peptide loop (residues 278-285) exhibiting dynamic motions during catalysis and modified it via residue insertions. We evaluated these loop mutants using computer simulations, substrate kinetics, resistance to inhibition, and enzyme reactivation assays using both the choline ester and OP substrates. A slight but significant increase in reactivation was noted with paraoxon with one of the mutants, and changes in KM and catalytic efficiency were noted in others. Simulations suggested weaker interactions between OP versus choline substrates and the active site of all engineered versions of the enzyme. The results indicate that an improvement of OP anticholinesterase hydrolysis through surface loop engineering may be a more effective strategy in an enzyme with higher intrinsic OP compound hydrolase activity. |
| Databáze: | OpenAIRE |
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