MICROBIAL SPERMIDINE DEHYDROGENASE - PURIFICATION AND PROPERTIES OF THE ENZYME IN PSEUDOMONAS-AERUGINOSA AND CITROBACTER-FREUNDII

Spermidine dehydrogenases were purified from Pseudomonas aeruginosa and Citrobacter freundii. P. aeruginosa cells contained only one constitutive spermidine dehydrogenase. C. freundii cells contained two kinds of spermidine dehydrogenases (I and II) and both were induced in the presence of substrate, spermidine. The enzymes purified from the two strains consisted of a single polypeptide chain with a molecular weight of about 63,000. The enzymes (I and II) in C. freundii had a sharp absorbance peak at 430 nm and showed the same N-terminal amino acid sequences (Ser-Gly-Lys-Gly-Asn-). The enzymes in P. aeruginosa and C. freundii specifically oxidized spermidine and spermine in the presence of electron acceptors such as potassium ferrycyanide and 2, 6-dichlorophenolindophenol. © 1990.