The biosynthetic pathway of new polyamines in Caldariella acidophila

Abstract

1. Spermidine and sym-nor-spermine (1,11-diamino-4,8-diazaundecane) were identified as the major components of the polyamine pool in Caldariella acidophila, an extreme thermoacidophilic bacterium. A minor component, a new polyamine, sym-nor-spermidine (1,7-diamino-4-azaheptane) was isolated and characterized. 2. To elucidate the biosynthetic pathway, labelled methionine, putrescine, spermidine and spermine were fed to Caldariella acidophila. Incubation of the bacterium in the presence of putrescine or spermidine labelled in the tetramethylene moiety gave unlabelled sym-nor-spermidine and sym-nor-spermine, whereas the radioactivity of propylamine-labelled methionine or spermidine was incorporated into these molecules. No radioactivity was recovered in the polyamines pool when spermine was fed to Caldariella acidophila. 3. S-Adenosylmethionine and S-(5′-adenosyl)-3-methylthiopropylamine were identified as intermediates of the biosynthetic pathway; the cellular contents of the two sulphonium compounds, measured with a new isotope-dilution technique, are 60 and 15nmol/g wet wt. of cells respectively. 4. The above results are indicative of a new pathway characterized by three propylamine-transfer reactions, decarboxylated S-adenosylmethionine being the common donor of the propylamine moiety. The reactions yielding sym-nor-spermidine and sym-nor-spermine are reported for the first time. 5. The probable intermediates related to the catabolism of the tetramethylene moiety of spermidine, γ-aminobutyraldehyde, γ-aminobutyric acid or Δ1-pyrroline were not detectable. Experiments with [3-aminopropyl-3(n)-3H]spermidine trihydrochloride plus [tetramethylene-1,4-14C]spermidine trihydrochloride gave rise to an amount of labelled CO2 equivalent to the spermidine catabolized.

S‐Adenosylmethionine synthetase in the thermophilic archaebacterium Sulfolobus solfataricus.

“…The occurrence of AdoMet in S. solfutaricus has been reported for the first time in our laboratory [7]. The cellular concentration of the sulfonium compound in this microorganism is similar to that reported in eukaryotes [l-41.…”

“…There is a general agreement that the y form is the major, if not the only form, in normal nonhepatic tissues of rat and man [20,23, 251. It is interesting to note, in this respect, that the antiserum against the j l form was shown to cross-react with the a form but not with the y form [22].The occurrence of AdoMet in S. solfutaricus has been reported for the first time in our laboratory [7]. The cellular concentration of the sulfonium compound in this microorganism is similar to that reported in eukaryotes [l-41.…”

The First Agmatine/Cadaverine Aminopropyl Transferase: Biochemical and Structural Characterization of an Enzyme Involved in Polyamine Biosynthesis in the Hyperthermophilic Archaeon Pyrococcus furiosus

“…The polyamine pool of the hyperthermophilic archaeon S. solfataricus is indeed characterized by two unusual polyamines, sym-nor-spermidine and sym-nor-spermine (12,13). The peculiar carbon chain lengths and charge distributions of these symmetrical polycations could facilitate specific interactions with nucleic acids, resulting in a protection of DNA against thermal denaturation.…”

Detection of Norspermidine and Norspermine in Medicago sativa L. (Alfalfa)

“…First, the occurrence of norspermidine and norspermine in alfalfa implicates a previously unrecognized biosynthetic pathway in higher plants. These reactions could proceed through successive additions of an aminopropyl moiety from decarboxylated S-adenosylmethionine by the action of an aminopropyltransferase enzyme, beginning with the precursor 1,3-diaminopropane, as proposed for thermophilic bacteria (7). We speculate that a nonspecific aminopropyltransferase may exist in alfalfa that catalyzes elongation of 1,3-diaminopropane to norspermidine, and norspermidine to norspermine.…”