Purification and spectroscopic studies on catechol oxidase from lemon balm (Melissa officinalis)

► A catechol oxidase from lemon balm (Melissa officinalis) has been purified to identity. ► The molecular mass of the M. officinalis enzyme was determined to 39,370 Da and the isoelectric point to 3.4. ► Addition of 2 eq. H2O2 to the enzymes leads to oxy catechol oxidase, characteristic for type 3 copper proteins. ► The N-terminal sequence hast been determined by Edman degradation to NPVQAPELDKCGTAT.