Reaction: S-adenosyl 3-(methylsulfanyl)propylamine + spermidine = S-methyl-5'-thioadenosine + spermine
For diagram of reaction click here.
Glossary: spermidine = N-(3-aminopropyl)butane-1,4-diamine
spermine = N,N'-bis(3-aminopropyl)butane-1,4-diamine
S-adenosyl 3-(methylsulfanyl)propylamine = (3-aminopropyl){[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxytetrahydrofuran-2-yl]methyl}methylsulfonium
Other name(s): spermidine aminopropyltransferase; spermine synthetase; S-adenosylmethioninamine:spermidine 3-aminopropyltransferase; S-adenosyl 3-(methylthio)propylamine:spermidine 3-aminopropyltransferase
Systematic name: S-adenosyl 3-(methylsulfanyl)propylamine:spermidine 3-aminopropyltransferase
Comments: The enzyme from mammalia is highly specific for spermidine [2,3]. cf. EC 2.5.1.16 (spermidine synthase) and EC 2.5.1.23 (sym-norspermidine synthase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 74812-43-4
References:
1. Hibasami, H., Borchardt, R.T., Chen, S.-Y., Coward, J.K. and Pegg, A.E. Studies of inhibition of rat spermidine synthase and spermine synthase. Biochem. J. 187 (1980) 419-428. [PMID: 7396856]
2. Pajula, R.-L., Raina, A. and Eloranta, T. Polyamine synthesis in mammalian tissues. Isolation and characterization of spermine synthase from bovine brain. Eur. J. Biochem. 101 (1979) 619-626. [PMID: 520313]
3. Pegg, A.E., Shuttleworth, K. and Hibasami, H. Specificity of mammalian spermidine synthase and spermine synthase. Biochem. J. 197 (1981) 315-320. [PMID: 6798961]