Homospermidine synthase explained

Homospermidine synthase
Ec Number:	2.5.1.44
Cas Number:	76106-84-8

Homospermidine synthase is an enzyme with systematic name putrescine:putrescine 4-aminobutyltransferase (ammonia-forming).^{[1] [2] [3] [4] [5] [6]} This enzyme catalyses the following chemical reaction

\rightleftharpoons sym-homospermidine + NH₃ + H⁺\rightleftharpoons sym-homospermidine + propane-1,3-diamine

The reaction of this enzyme occurs in three steps.

Notes and References

1. Tait GH . The formation of homospermidine by an enzyme from Rhodopseudomonas viridis [proceedings] . Biochemical Society Transactions . 7 . 1 . 199–201 . February 1979 . 437275 . 10.1042/bst0070199.
2. Biosynthesis of pyrrolizidine alkaloids: putrescine and spermidine are essential substrates of enzymatic homospermidine formation . Böttcher F, Ober D, Hartmann T . Can. J. Chem. . 1994 . 72 . 80–85 . 10.1139/v94-013 . free .
3. Yamamoto S, Nagata S, Kusaba K . Purification and characterization of homospermidine synthase in Acinetobacter tartarogenes ATCC 31105 . Journal of Biochemistry . 114 . 1 . 45–9 . July 1993 . 8407874 . 10.1093/oxfordjournals.jbchem.a124137.
4. Srivenugopal KS, Adiga PR . Enzymic synthesis of sym-homospermidine in Lathyrus sativus (grass pea) seedlings . The Biochemical Journal . 190 . 2 . 461–4 . August 1980 . 7470060 . 1162113 . 10.1042/bj1900461.
5. Homospermidine synthase of Rhodopseudomonas viridis: Substrate specificity and effects of the heterologously expressed enzyme on polyamine metabolism of Escherichia coli . Ober D, Tholl D, Martin W, Hartmann T . J. Gen. Appl. Microbiol. . 1996 . 42 . 411–419 . 10.2323/jgam.42.411 . 5 . free .
6. Ober D, Hartmann T . Homospermidine synthase, the first pathway-specific enzyme of pyrrolizidine alkaloid biosynthesis, evolved from deoxyhypusine synthase . Proceedings of the National Academy of Sciences of the United States of America . 96 . 26 . 14777–82 . December 1999 . 10611289 . 24724 . 10.1073/pnas.96.26.14777 . 1999PNAS...9614777O . free .