| Autor: |
Sherwood, Roger F., Melton, Roger C., Alwan, Shakir M., Hughes, Peter |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 5/2/85, Vol. 148 Issue 3, p447-453, 7p |
| Abstrakt: |
A folate-degrading enzyme, carboxypeptidase G2, has been purified on a large scale from Pseudomonas sp. strain RS-16. Homogeneous enzyme was obtained by a three-step procedure involving ion-exchange chromatography and a novel triazine dye (affinity) chromatography step which utilizes Zn2+ to promote adsorption of the enzyme. Enzyme was selectively eluted by the use of a chelating agent (EDTA) and a step change in pH. The enzyme is a dimeric protein (Mr 83000) with two identical subunits follows and contains four atoms of zinc per enzyme molecule, which are required for full activity. The enzyme follows Michaelis-Menten kinetics with Km values of 4.0 μM for folate, 8.0 μM for methotrexate and 34.0 μM for 5-methyltetrahydrofolate, the predominant form of reduced folate found in plasma. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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