5mbx
From Proteopedia
Crystal structure of reduced murine N1-acetylpolyamine oxidase in complex with N1-acetylspermine
Structural highlights
FunctionPAOX_MOUSE Flavoenzyme which catalyzes the oxidation of N(1)-acetylspermine to spermidine and is thus involved in the polyamine back-conversion. Can also oxidize N(1)-acetylspermidine to putrescine. Substrate specificity: N(1)-acetylspermine = N(1)-acetylspermidine > N(1),N(12)-diacylspermine >> spermine. Does not oxidize spermidine. Plays an important role in the regulation of polyamine intracellular concentration and has the potential to act as a determinant of cellular sensitivity to the antitumor polyamine analogs. Publication Abstract from PubMedN1-Acetylspermine oxidase (APAO) catalyzes the conversion of N1-acetylspermine or N1-acetylspermidine to spermidine or putrescine, respectively, with concomitant formation of N-acetyl-3-aminopropanal and hydrogen peroxide. Here we present the structure of murine APAO in its oxidized holo form and in complex with substrate. The structures provide a basis for understanding molecular details of substrate interaction in vertebrate APAO, highlighting a key role for an asparagine residue in coordinating the N1-acetyl group of the substrate. We applied computational methods to the crystal structures to rationalize previous observations with regard to the substrate charge state. The analysis suggests that APAO features an active site ideally suited for binding of charged polyamines. We also reveal the structure of APAO in complex with the irreversible inhibitor MDL72527. In addition to the covalent adduct, a second MDL72527 molecule is bound in the active site. Binding of MDL72527 is accompanied by altered conformations in the APAO backbone. On the basis of structures of APAO, we discuss the potential for development of specific inhibitors. The Structure of Murine N1-Acetylspermine Oxidase Reveals Molecular Details of Vertebrate Polyamine Catabolism.,Sjogren T, Wassvik CM, Snijder A, Aagaard A, Kumanomidou T, Barlind L, Kaminski TP, Kashima A, Yokota T, Fjellstrom O Biochemistry. 2017 Jan 12. doi: 10.1021/acs.biochem.6b01140. PMID:28029774[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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