Spermine oxidase (SMO) is a flavoenzyme involved in polyamine homeostasis in animal cells. Themouse spermine oxidasegene (mSMO) codes for splicevariants, including the previously reportedmajor active isoform, herein named alfa (a). In the present work, eight additional gene splicing variants were characterized. The heterologous expression and biochemical characterization ofthree recombinant iso-forms (namely mSMOl,-cand -d) revealed that only the recombinant protein mSMOldisplays biochemical charac-.
