1. A structure-activity study to identify novel and efficient substrates of the human semicarbazide-sensitive amine oxidase/VAP-1 enzyme
- Author
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Michele Lunelli, Marina Scarpa, Gabriella Milan, Emanuela Bonaiuto, Maria Luisa Di Paolo, and Roberto Vettor
- Subjects
Models, Molecular ,Amine oxidase ,Biochemistry ,Structure-Activity Relationship ,chemistry.chemical_compound ,Benzylamine ,Catalytic Domain ,Drug Discovery ,Adipocytes ,Humans ,Structure–activity relationship ,Amines ,pH dependence ,chemistry.chemical_classification ,biology ,Chemistry ,Cell Membrane ,Osmolar Concentration ,Amine oxidase (copper-containing) ,Active site ,Semicarbazide-sensitive amine oxidases ,General Medicine ,Hydrogen-Ion Concentration ,Recombinant Proteins ,Computational docking ,Semicarbazides ,Kinetics ,Enzyme ,Docking (molecular) ,Butanes ,biology.protein ,Amine Oxidase (Copper-Containing) ,SSAO/VAP-1 substrates ,Structure-function relationships ,Diamine oxidase ,Cell Adhesion Molecules ,Protein Binding - Abstract
Kinetic studies were performed with various alkanamines as "substrate probes" of the properties of the active site of the human semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 (SSAO/VAP-1). We found that the enzyme-substrate recognition step is mainly controlled by apolar interactions and that a "good" substrate has a molecular structure containing a long aliphatic chain and a second positive charge at a distance greater than 12 A from the reactive amino group. In this context, we identified a novel substrate for the human SSAO/VAP-1, 1,12-diaminododecane (DIADO), which is characterised by the highest catalytic efficiency reported to date in comparison to the prototypic substrate benzylamine. Computational docking studies revealed the structural basis of this behaviour, highlighting the key role played by Lys393 in hindering substrate docking. Maximum SSAO/VAP-1 activity is reached at relatively low concentrations of DIADO (10-30 microM), and, in these conditions, it has good selectivity: it is a good substrate of SSAO/VAP-1 but not of human adipocyte monoamine oxidases or pig kidney diamine oxidase. From these findings, it appears that DIADO can be used as a new substrate for human SSAO/VAP-1 to elicit glucose transport into adipocytes, and may consequently have potential pharmacological applications in the design of anti-diabetic agents.
- Published
- 2010