Biochemical characterization and homology modeling of polyamine oxidase from cyanobacterium Synechocystis sp. PCC 6803.

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Samasil K, Lopes de Carvalho L, Mäenpää P, Salminen TA, Incharoensakdi A
Publisher: Elsevier
Publication year: 2017
Journal: Plant Physiology and Biochemistry
Journal acronym: Plant Physiol Biochem
Volume number: 119
Start page: 159
End page: 169
ISSN: 1873-2690
eISSN: 1873-2690


Abstract

The intracellular polyamine contents are regulated not only by polyamine biosynthesis and transport but also by polyamine degradation catalyzed by copper-dependent amine oxidase (DAO) and FAD-dependent polyamine oxidase (PAO). The genome sequence of Synechocystis sp. PCC 6803 reveals the presence of at least one putative polyamine oxidase gene, slr5093. The open reading frame of slr5093 encoding Synechocystis polyamine oxidase (SynPAO, E.C. 1.5.3.17) was expressed in Escherichia coli. The purified recombinant enzyme had the characteristic absorption spectrum of a flavoprotein with absorbance peaks at 380 and 450 nm. The optimum pH and temperature for the oxidation of both spermidine and spermine are 8.5 and 30 °C, respectively. The enzyme catalyzed the conversion of spermine and spermidine to spermidine and putrescine, respectively, with higher catalytic efficiency when spermine served as substrate. These results suggest that SynPAO is a polyamine oxidase involved in a polyamine back-conversion pathway. Based on the structural analysis, Gln94, Tyr403 and Thr440 in SynPAO are predicted to be important residues in the active site.

Last updated on 2019-18-10 at 01:05