Complex N-acetylation of triethylenetetramine.
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Cerrada-Gimenez M, Weisell J, Hyvonen MT, Park MH, Alhonen L, Vepsalainen J, Keinanen TA
Complex N-acetylation of triethylenetetramine.
Drug Metab Dispos. 2011 Dec;39(12):2242-9. doi: 10.1124/dmd.111.041798. Epub 2011 Aug 30.
- PubMed ID
- 21878558 [ View in PubMed]
- Abstract
Triethylenetetramine (TETA) is an efficient copper chelator that has versatile clinical potential. We have recently shown that spermidine/spermine-N(1)-acetyltransferase (SSAT1), the key polyamine catabolic enzyme, acetylates TETA in vitro. Here, we studied the metabolism of TETA in three different mouse lines: syngenic, SSAT1-overexpressing, and SSAT1-deficient (SSAT1-KO) mice. The mice were sacrificed at 1, 2, or 4 h after TETA injection (300 mg/kg i.p.). We found only N(1)-acetyltriethylenetetramine (N(1)AcTETA) and/or TETA in the liver, kidney, and plasma samples. As expected, SSAT1-overexpressing mice acetylated TETA at an accelerated rate compared with syngenic and SSAT1-KO mice. It is noteworthy that SSAT1-KO mice metabolized TETA as syngenic mice did, probably by thialysine acetyltransferase, which had a K(m) value of 2.5 +/- 0.3 mM and a k(cat) value of 1.3 s(-1) for TETA when tested in vitro with the human recombinant enzyme. Thus, the present results suggest that there are at least two N-acetylases potentially metabolizing TETA. However, their physiological significance for TETA acetylation requires further studies. Furthermore, we detected chemical intramolecular N-acetyl migration from the N(1) to N(3) position of N(1)AcTETA and N(1),N(8)-diacetyltriethylenetetramine in an acidified high-performance liquid chromatography sample matrix. The complex metabolism of TETA together with the intramolecular N-acetyl migration may explain the huge individual variations in the acetylation rate of TETA reported earlier.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Triethylenetetramine Diamine acetyltransferase 1 Protein Humans UnknownSubstrateDetails - Drug Reactions
Reaction Details
