| Autor: |
Hiraga, Akira, Kikuchi, Kunimi, Tamura, Shinri, Tsuiki, Shigeru |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 10/15/81, Vol. 119 Issue 3, p503-510, 8p |
| Abstrakt: |
Phosphoprotein phosphatase IA, which represents the major glycogen synthase phosphatase activity in rat liver cytosol, has been purified to apparent homogeneity by chromatography on DEAE-cellulose, histone - Sepharose-48 and Sephadex G-100. The molecular weight of the purified enzyme was 40000 by gel filtration and 48 000 by sodium dodecyl sulafte get electrophoresis. Phosphatase IA is therefore a monomeric protein. When treated with 80 % ethanol at room temperature, phosphatase IA underwent an inactivation which was totally prevented by 2 mM MgCI2. Catalytically, phosphatase IA has a preference for glycogen synthase ID compared with phosphatases lB and II and obligatorily requires Mg24 or Mn2 + for activity. Maximum activity was attained at 5 m MgCI2. Since Mg2" does not activate other phosphoprotein phosphatases in rat liver cytosol, we propose the term Mg2 f-dependent glycogen synthase phosphatase' for phosphatase IA. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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