Computer-aided rational protein design was demonstrated to be effective in addressing important issues in chemistry and biology. With computer simulation, a structural and functional nitric oxide reductase (NOR) was successfully designed using myoglobin (Mb) as a protein model, which was accomplished at the time with no three dimensional structure available for NOR itself. More importantly, the designed NOR protein model, Fe BMb, was confirmed by an X-ray structure of native NOR one year later. The progress and rationalities of design of Fe BMb, I107E Fe BMb, as well as Fe BMb(-His), were revi...