4-aminobutanal + propane-1,3-diamine + AH2 => spermidine + A + H2O
4-aminobutanal + propane-1,3-diamine + ah2 => spermidine + a + h2o
4-aminobutanal + propane-1,3-diamine + AH2 => spermidine + A + H2O
4-aminobutanal + propane-1,3-diamine + ah2 => spermidine + a + h2o