Calmodulin binding to inducible nitric-oxide synthase may play an important role in its Ca2+-independent activity. Studies of inducible nitric-oxide synthase chimeras containing the calmodulin binding sequence of neuronal or endothelial nitric-oxide synthases show that the calmodulin binding sequence of inducible nitric-oxide synthase is necessary but not sufficient for the Ca2+-independent activity. The mutations at lysine 525 located at the C terminus of the calmodulin binding sequence of inducible nitric-oxide synthase were examined for the effects on the Ca2+-independent activity with chimeras containing the oxygenase or reductase domains of inducible or neuronal nitric-oxide synthases. Results show that the Ca2+-independent binding of calmodulin is not solely responsible for maximal Ca2+-independent activity of inducible nitric-oxide synthase. Lysine 525 of inducible nitric-oxide synthase may also play an important role in coordinating the maximal Ca2+-independent activity.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - Nov 17 2000|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology