| Title: | Moth chemosensory protein exhibits drastic conformational changes and cooperativity on ligand binding |
| Author(s): | Campanacci V; Lartigue A; Hallberg BM; Jones TA; Giudici-Orticoni MT; Tegoni M; Cambillau C; |
| Address: | "Architecture et Fonction des Macromolecules Biologiques, Unite Mixte de Recherche 6098, Centre National de la Recherche Scientifique and Universites d'Aix-Marseille I & II, 31 Chemin J. Aiguier, 13402 Marseille Cedex 20, France" |
| ISSN/ISBN: | 0027-8424 (Print) 1091-6490 (Electronic) 0027-8424 (Linking) |
| Abstract: | "Chemosensory proteins (CSPs) have been proposed to transport hydrophobic chemicals from air to olfactory or taste receptors. They have been isolated from several sensory organs of a wide range of insect species. The x-ray structure of CSPMbraA6, a 112-aa antennal protein from the moth Mamestra brassicae (Mbra), was shown to exhibit a novel type of alpha-helical fold. We have performed a structural and binding study of CSPMbraA6 to get some insights into its possible molecular function. Tryptophan fluorescence quenching demonstrates the ability of CSPMbraA6 to bind several types of semio-chemicals or surrogate ligands with microM K(d). Its crystal structure in complex with one of these compounds, 12-bromo-dodecanol, reveals extensive conformational changes on binding, resulting in the formation of a large cavity filled by three ligand molecules. Furthermore, binding cooperativity was demonstrated for some ligands, suggesting a stepwise binding. The peculiar rearrangement of CSPMbraA6 conformation and the cooperativity phenomenon might trigger the recognition of chemicals by receptors and induce subsequent signal transduction" |
| Keywords: | "Animals Insect Proteins/chemistry/genetics/*metabolism Ligands Models, Molecular Moths Mutagenesis, Site-Directed Protein Binding Protein Conformation Spectrometry, Fluorescence Tryptophan/metabolism;" |
| Notes: | "MedlineCampanacci, Valerie Lartigue, Audrey Hallberg, B Martin Jones, T Alwyn Giudici-Orticoni, Marie-Therese Tegoni, Mariella Cambillau, Christian eng Research Support, Non-U.S. Gov't 2003/04/17 Proc Natl Acad Sci U S A. 2003 Apr 29; 100(9):5069-74. doi: 10.1073/pnas.0836654100. Epub 2003 Apr 15" |
