Ground-State Electronic Destabilization via Hyperconjugation in Aspartate Aminotransferase
| Autor: | Wait R. Griswold, Michael D. Toney, Joan Nieto Castro, Andrew J. Fisher |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Models
Molecular Aldimine Direct evidence Stereochemistry Electrons Hyperconjugation Biochemistry Article Catalysis Substrate Specificity chemistry.chemical_compound Colloid and Surface Chemistry Pyridine Kinetic isotope effect Escherichia coli Point Mutation Transferase Aspartate Aminotransferases chemistry.chemical_classification Aspartic Acid General Chemistry chemistry Pyridoxal Phosphate Imines Ground state |
| Zdroj: | Journal of the American Chemical Society. 134:8436-8438 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Binding isotope effects for l-aspartate reacting with the inactive K258A mutant of PLP-dependent aspartate aminotransferase to give a stable external aldimine intermediate are reported. They provide direct evidence for electronic ground-state destabilization via hyperconjugation. The smaller equilibrium isotope effect with deazaPLP-reconstituted K258A indicates that the pyridine nitrogen plays an important role in labilizing the Cα-H bond. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|