Table 2. In vitro assay showing substrate specificity
Substrate Product assayed Polyamine oxidase activity, nmol per mg of protein per min
Spermine Spermidine 390
N1-Acetylspermine Spermidine 800
N1-Acetylspermidine Putrescine 270
  • Substrates (1 mM) were incubated in the presence of partially purified (≈80%) His-tagged Fms1 protein as mentioned in Materials and Methods, and, after 30 min, reactions were stopped. Activity was measured on the basis of amine conversion (appearance of amine product) as determined by HPLC analysis. No oxidation was observed by using spermidine or putrescine as substrate (data not shown).