Abstract
Neuronal NO synthase (nNOS) was discovered recently to interact specifically with the protein PIN (protein inhibitor of nNOS) [Jaffrey, S.R. and Snyder, S.H. (1996) Science 274, 774-777]. We have studied the effects on pure NOS enzymes of the same GST-tagged PIN used in the original paper. Unexpectedly, all NOS isoenzymes were inhibited. The IC50 for nNOS was 18 +/- 6 microM GST-PIN with 63 nM nNOS after 30 min at 37 degrees C. Uncoupled NADPH oxidation was inhibited similarly, whereas cytochrome c reductase activity, the K(M) for L-arginine, and dimerization were unaffected. We reconsider the physiological role of PIN in the light of these results.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Carrier Proteins / genetics
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Carrier Proteins / pharmacology*
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Cytochrome c Group / metabolism
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Dimerization
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Drosophila Proteins*
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Dyneins
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Enzyme Inhibitors / pharmacology
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NADP / metabolism
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Nitric Oxide Synthase / antagonists & inhibitors*
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Nitric Oxide Synthase / chemistry
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Nitric Oxide Synthase / metabolism
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Nitric Oxide Synthase Type I
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Nitric Oxide Synthase Type II
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Nitric Oxide Synthase Type III
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Oxidation-Reduction
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Rats
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Recombinant Fusion Proteins
Substances
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Carrier Proteins
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Cytochrome c Group
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Drosophila Proteins
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Enzyme Inhibitors
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Recombinant Fusion Proteins
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NADP
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Nitric Oxide Synthase
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Nitric Oxide Synthase Type I
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Nitric Oxide Synthase Type II
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Nitric Oxide Synthase Type III
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Nos1 protein, rat
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Nos2 protein, rat
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Nos3 protein, rat
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Dyneins