| Autor: |
Callery, P. S., Nayar, M. S. B., Geelhaar, L. A. |
| Zdroj: |
Biomedical Mass Spectrometry; March 1984, Vol. 11 Issue: 3 p118-120, 3p |
| Abstrakt: |
The deamination of putrescine catalysed by diamine oxidase was carried out in deuterium oxide and deuterated buffers. Enamine and a,ß-unsaturated intermediates were excluded, based on the observation that deuterium was not incorporated into ?1-pyrroline during its enzymatic formation in deuterium oxide. When the reaction mixture was buffered with phosphate, isolated ?1-pyrroline contained two deuterium atoms at C-3, indicating that a phosphate-promoted, non-enzymatic isotope exchange had occurred. Using 5,5-dimethyl-?1-pyrroline as a model compound, the nature of the non-enzymatic deuterium exchange was studied and a bifunctional catalysis mechanism proposed. The results suggest that the choice of buffer could alter the conclusions drawn from enzyme mechanism studies involving imine-enamine tautomerism. |
| Databáze: |
Supplemental Index |
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