| Autor: |
Pribilla, Iris, Krüger, Helmut, Buchner, Klaus, Otto, Henning, Schiebler, Werner, Tripier, Dominique, Hucho, Ferdinand |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 11/15/88, Vol. 177 Issue 3, p657-664, 8p |
| Abstrakt: |
Bovine brain cytosol is shown to contain two heat-resistant inhibitors of protein kinase C, with the following characteristics: 1. One protein kinase C inhibitor can be easily purified to homogeneity. Evidence is presented that this polypeptide of Mr 19000 is calmodulin. It inhibits protein kinase C with an EC50 of about 2.5 μM and the inhibition is Ca2+-independent. It inhibits only intact protein kinase C. Removal of the regulatory domain of protein kinase C, by limited proteolysis with trypsin, abolishes the inhibition. 2. Another protein kinase C inhibitory activity has been partially purified. Its Mr is low (Mr 600–700, as estimated by gel chromatography). It is not digested by proteases, is hydrophilic, acid- and alkali-resistant, acts Ca2+-independently, and, in contrast to calmodulin, inhibits even the catalytic fragment of protein kinase C after removal of the regulatory domain by limited proteolysis. This inhibition is, at least partially, due to a competition with ATP. Besides protein kinase C, calcium/calmodulin-dependent protein kinase II is inhibited to a similar extent. cAMP-dependent protein kinase is not affected. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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