High-level expression of functional rat neuronal nitric oxide synthase in Escherichia coli Academic Article Article uri icon


MeSH Major

  • Computational Biology
  • Expressed Sequence Tags
  • Gene Expression Profiling
  • Proteins


  • The neuronal nitric oxide synthase (nNOS) has been successfully overexpressed in Escherichia coli, with average yields of 125-150 nmol (20-24 mg) of enzyme per liter of cells. The cDNA for nNOS was subcloned into the pCW vector under the control of the tac promotor and was coexpressed with the chaperonins groEL and groES in the protease-deficient BL21 strain of E. coli. The enzyme produced is replete with heme and flavins and, after overnight incubation with tetrahydrobiopterin, contains 0.7 pmol of tetrahydrobiopterin per pmol of nNOS. nNOS is isolated as a predominantly high-spin heme protein and demonstrates spectral properties that are identical to those of nNOS isolated from stably transfected human kidney 293 cells. It binds N omega-nitroarginine dependent on the presence of bound tetrahydrobiopterin and exhibits a Kd of 45 nM. The enzyme is completely functional; the specific activity is 450 nmol/min per mg. This overexpression system will be extremely useful for rapid, inexpensive preparation of large amounts of active nNOS for use in mechanistic and structure/function studies, as well as for drug design and development.

publication date

  • August 29, 1995



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1073/pnas.92.18.8428

PubMed ID

  • 7545302

Additional Document Info

start page

  • 8428

end page

  • 32


  • 92


  • 18