| Autor: |
Trapeznikova SS, Navasardiants DG, Davtian MA |
| Jazyk: |
ruština |
| Zdroj: |
Biokhimiia (Moscow, Russia) [Biokhimiia] 1982 Dec; Vol. 47 (12), pp. 2022-7. |
| Abstrakt: |
Two differently charged isoforms of arginase were isolated from rat liver and partially purified. The isoelectric point for isoform I possessing more than 90% of the total arginase activity lies around 9.3, while that for isoform II lies around pH 7.0. Both isoforms have similar molecular weights (120,000) and close Km values (1-3 mM). In order to stabilize the enzyme activity both isoforms were obtained in an immobilized state. Study of the effects of some cholate compounds, SH-reagents and inhibitors on soluble and immobilized isoforms revealed some differences in the properties of these isoforms. Isoform II subunits are more tightly bound to Mn2+ than those of isoform I; the role of SH-groups in manifestation of the catalytic activity of the isoforms appears to be different. Isoform I possessing a positive charge (this is in agreement with the literary data) can be related to ureothelic enzymes, while isoform II is close to non-ureothelic arginases from brain and kidney not coupled with the ammonium detoxication mechanism. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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