Disclosed herein are methods that may be used for the synthesis of benzylisoquinoline alkaloids (BIAs) such as alkaloid morphinan. The methods disclosed can be used to produce thebaine, oripavine, codeine, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone, naltrexone, naloxone, hydroxycodeinone, neopinone, and/or buprenorphine.

The present invention provides, among other things, methods and compositions for making and using recombinant heme oxygenase for treating sickle cell disease. In some embodiments, recombinant heme oxygenase proteins are truncation variants, or Fc fusion proteins with increased half-life and/or reduced aggregation.