Identification of an imidazoline binding protein: Creatine kinase and an imidazoline-2 binding site
| Autor: | James J. Robinson, Alan L. Hudson, David J. Nutt, Robin J. Tyacke, Atsuko Kimura, Michael C.W. Minchin, Stephen M. Husbands |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Research Report
Male Models Molecular 2-BFI 2-(2-benzofuranyl)2-imidazoline MOE molecular operating environment Imidazoline binding protein 2-BFI Imidazoline receptor BU224 2-(4 5-dihydroimidaz-2-yl)quinoline 0302 clinical medicine GR glucose-responsive 0303 health sciences GOLD genetic optimisation for ligand docking General Neuroscience Imidazoles Brain 3. Good health I2 imidazoline-2 subtype Biochemistry Female Rabbits Binding domain MAO monoamine oxidase Neuroscience(all) Clinical Neurology Biology DNA-binding protein 03 medical and health sciences Affinity chromatography Creatine Kinase BB Form Chemical specificity Animals Creatine kinase Rats Wistar Binding site BU99006 5-isothiocyanoato-2-benzofuranyl-2-imidazoline Molecular Biology Benzofurans 030304 developmental biology Binding Sites Dose-Response Relationship Drug Binding protein Cell Membrane Cooperative binding Harmane and psychiatric disorders Rats Enzyme Activation KATP channel ATP sensitive potassium channel B-CK brain creatine kinase Imidazoline Receptors Neurology (clinical) Chickens CK creatine kinase 030217 neurology & neurosurgery Developmental Biology |
| Zdroj: | Brain Research |
| ISSN: | 0006-8993 |
| DOI: | 10.1016/j.brainres.2009.04.044 |
| Popis: | Drugs that bind to imidazoline binding proteins have major physiological actions. To date, three subtypes of such proteins, I(1), I(2) and I(3), have been proposed, although characterisations of these binding proteins are lacking. I(2) binding sites are found throughout the brain, particularly dense in the arcuate nucleus of the hypothalamus. Selective I(2) ligands demonstrate antidepressant-like activity and the identity of the proteins that respond to such ligands remained unknown until now. Here we report the isolation of a approximately 45 kDa imidazoline binding protein from rabbit and rat brain using a high affinity ligand for the I(2) subtype, 2-BFI, to generate an affinity column. Following protein sequencing of the isolated approximately 45 kDa imidazoline binding protein, we identified it to be brain creatine kinase (B-CK). B-CK shows high binding capacity to selective I(2) ligands; [(3)H]-2-BFI (5 nM) specifically bound to B-CK (2330+/-815 fmol mg protein(-1)). We predicted an I(2) binding pocket near the active site of B-CK using molecular modelling. Furthermore, B-CK activity was inhibited by a selective I(2) irreversible ligand, where 20 microM BU99006 reduced the enzyme activity by 16%, confirming the interaction between B-CK and the I(2) ligand. In summary, we have identified B-CK to be the approximately 45 kDa imidazoline binding protein and we have demonstrated the existence of an I(2) binding site within this enzyme. The importance of B-CK in regulating neuronal activity and neurotransmitter release may well explain the various actions of I(2) ligands in brain and the alterations in densities of I(2) binding sites in psychiatric disorders. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect