Arginine deiminase: Demonstration of two active sites and possible half-of-the-sites reactivity
| Autor: | Douglas W. Smith, Michael E. Himmel, David E. Fahrney, Joachim L. Weickmann |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
chemistry.chemical_classification
Binding Sites biology Hydrolases DTNB Stereochemistry Affinity label Biophysics Cell Biology Arginine Biochemistry Peptide Fragments Catalysis Molecular Weight Mycoplasma Formamidinium Enzyme chemistry biology.protein Centrifugation Reactivity (chemistry) Molecular Biology Arginine deiminase Protein Binding |
| Zdroj: | Biochemical and Biophysical Research Communications. 83:107-113 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/0006-291x(78)90404-7 |
| Popis: | Arginine deiminase (EC 3.5.3.6) from Mycoplasma arthritidis is a dimeric enzyme. Velocity centrifugation in 6 M guanidine HCl and peptide mapping of the BrCN fragments suggest that the subunits are identical. The reaction of one out of four sulfhydryl groups with 0.3 mM 5,5′-dithiobis-(2-nitrobenzoic acid) has a half-life of about 30 min in 2 M guanidine HCl at 15°, pH 8. The enzyme is irreversibly inhibited by 1 mM formamidinium ion within 1 min. Inactivation by this affinity label is resolvable into two concurrent first-order reactions in the presence of guanidinium ion; the fraction of enzyme which reacts at the faster rate is about 50%. These results are interpreted as evidence for two catalytic subunits which differ in conformation. |
| Databáze: | OpenAIRE |
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