Mechanism-based inhibitors of cytokinin oxidase/dehydrogenase attack FAD cofactor

Autor: Pierre Briozzo, David Kopečný, Marek Šebela, Lukáš Spíchal, Michel Laloue, Pavel Anzenbacher, Vlastimil Mašek, Nicole Houba-Hérin, Nathalie Joly, Catherine Madzak
Přispěvatelé: Department of biochemistry [Univ Palacký], Faculty of Science [Univ Palacký], Palacky University Olomouc-Palacky University Olomouc, Chimie Biologique (UCB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, biologie cellulaire, Institut National de la Recherche Agronomique (INRA), Microbiologie et Génétique Moléculaire (MGM), Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), department of biochemistry, Palacky University
Jazyk: angličtina
Rok vydání: 2008
Předmět:
Models
Molecular
Yarrowia lipolytica
MESH: Oxidation-Reduction
Cytokinins
MESH: Zea mays
MESH: Protein Structure
Secondary
Dehydrogenase
Protein Structure
Secondary
Substrate Specificity
Cytokinine
structure protéique
MESH: Recombinant Proteins
chemistry.chemical_compound
Protein structure
MESH: Structure-Activity Relationship
X-Ray Diffraction
Structural Biology
Enzyme Inhibitors
chemistry.chemical_classification
Flavin adenine dinucleotide
0303 health sciences
Molecular Structure
biology
MESH: Kinetics
030302 biochemistry & molecular biology
MESH: Models
Chemical
MESH: X-Ray Diffraction
Recombinant Proteins
Biochemistry
MESH: Enzyme Inhibitors
MESH: Flavin-Adenine Dinucleotide
Cytokinin
Flavin-Adenine Dinucleotide
MESH: Cytokinins
Oxidoreductases
Oxidation-Reduction
MESH: Models
Molecular
Protein Binding
Stereochemistry
MESH: Molecular Structure
Zea mays
Cofactor
Structure-Activity Relationship
03 medical and health sciences
expression hétérologue
Oxidoreductase
MESH: Protein Binding
MESH: Oxidoreductases
MESH: Hydrogen Bonding
Molecular Biology
030304 developmental biology
Binding Sites
Substrate (chemistry)
Hydrogen Bonding
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry
Molecular Biology/Molecular biology
Kinetics
Enzyme
Models
Chemical
chemistry
Flavine-Adenine Dinucleotide
MESH: Binding Sites
biology.protein
MESH: Substrate Specificity
Zdroj: Journal of Molecular Biology
Journal of Molecular Biology, Elsevier, 2008, 380 (5), pp.886-99. ⟨10.1016/j.jmb.2008.05.044⟩
ISSN: 0022-2836
1089-8638
DOI: 10.1016/j.jmb.2008.05.044⟩
Popis: International audience; Cytokinin oxidases/dehydrogenases (CKOs) mediate catabolic regulation of cytokinin levels in plants. Several substrate analogs containing an unsaturated side chain were studied for their possible inhibitory effect on maize CKO (ZmCKO1) by use of various bioanalytical methods. Two allenic derivatives, N(6)-(buta-2,3-dienyl)adenine (HA-8) and N(6)-(penta-2,3-dienyl)adenine (HA-1), were identified as strong mechanism-based inhibitors of the enzyme. Despite exhaustive dialysis, the enzyme remained inhibited. Conversely, substrate analogs with a triple bond in the side chain were much weaker inactivators. The crystal structures of recombinant ZmCKO1 complexed with HA-1 or HA-8 were solved to 1.95 A resolution. Together with Raman spectra of the inactivated enzyme, it was revealed that reactive imine intermediates generated by oxidation of the allenic inhibitors covalently bind to the flavin adenine dinucleotide (FAD) cofactor. The binding occurs at the C4a atom of the isoalloxazine ring of FAD, the planarity of which is consequently disrupted. All the compounds under study were also analyzed for binding to the Arabidopsis cytokinin receptors AHK3 and AHK4 in a bacterial receptor assay and for cytokinin activity in the Amaranthus bioassay. HA-1 and HA-8 were found to be good receptor ligands with a significant cytokinin activity. Nevertheless, due to their ability to inactivate CKO in the desired time intervals or developmental stages, they both represent attractive compounds for physiological studies, as the inhibition mechanism of HA-1 and HA-8 is mainly FAD dependent.
Databáze: OpenAIRE
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