Molecular cloning and expression of inducible nitric oxide synthase from human hepatocytes.

摘要: Abstract Nitric oxide is a short-lived biologic mediator for diverse cell types. Synthesis of an inducible nitric synthase (NOS) in murine macrophages stimulated by lipopolysaccharide (LPS) and interferon gamma. In human hepatocytes, NOS activity induced treatment with combination tumor necrosis factor, interleukin 1, gamma, LPS. We now report the molecular cloning expression hepatocyte (hep-NOS) cDNA. hep-NOS has 80% amino acid sequence homology to macrophage (mac-NOS). Like other isoforms, recognition sites FMN, FAD, NADPH are present, as well consensus calmodulin binding site. 293 kidney cells transfected cDNA diminished Ca2+ chelation antagonist, reflecting dependence not evident mac-NOS. Northern blot analysis reveals 4.5-kb mRNA both hepatocytes aortic smooth muscle following stimulation LPS cytokines. Human genomic Southern blots probed endothelial clones display different restriction enzyme fragments, suggesting distinct gene products these isoforms. appears be form that from mac-NOS brain isozymes.