Evidence for tryptophan residues being essential to the activity of papain.
D003545:Cysteine; D004789:Enzyme Activation; D005609:Free Radicals; D010206:Papain / Q000528:radiation effects*; D011830:Radiation Effects; D014364:Tryptophan
D005609:Free Radicals; D014364:Tryptophan; D010206:Papain; D003545:Cysteine