Expression of the fungal cytochrome P-450nor cDNA in Escherichia coli.

We succeeded in expressing the unique cytochrome P-450 (P-450), nitric oxide reductase (P-450nor), in Escherichia coli by utilizing P-450nor cDNA and the expression vector pKK233-2 or pUC19. The expression was confirmed by Western blot analysis and by detecting the unique nitric oxide reductase activity. The expressed protein was recovered in the soluble fraction of transformed cells, supporting that P-450nor is the first soluble P-450 of eukaryote. The results also provided conclusive evidence that the enzymatic reaction depends solely on P-450nor without support of any other electron transferring components.