There are two types of carbon monoxide dehydrogenase: one contains iron and molybdenum, the other contains iron and nickel. Parallels and differences in catalytic strategies have been reviewed.
Pb (lead) can replace Ca (calcium) as, for example, with calmodulin or Zn (zinc) as with metallocarboxypeptidases
Some other metalloenzymes are given in the following table, according to the metal involved.