Structure-Based Analysis of the Ligand-Binding Mechanism for DhelOBP21, a C-minus Odorant Binding Protein, from Dastarcus helophoroides (Fairmaire; Coleoptera: Bothrideridae)
| Autor: | De-Xin Kong, Shan-Cheng Yi, Man-Qun Wang, Yinan Zhang, Guang-Qiang Yu, Dong-Zhen Li |
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| Rok vydání: | 2015 |
| Předmět: |
Odorant binding
Receptors Odorant Polymerase Chain Reaction Applied Microbiology and Biotechnology Hydrophobic effect Bothrideridae Animals Molecule Homology modeling Odorant-binding proteins Site-directed mutagenesis Molecular Biology Ecology Evolution Behavior and Systematics molecular volume biology Dastarcus helophoroides hydrophobic interactions molecular docking Cell Biology biology.organism_classification Fluorescence Coleoptera Biochemistry fluorescence competitive binding assays Mutagenesis Site-Directed Biophysics Odorant-binding protein biology.protein site-directed mutagenesis Hydrophobic and Hydrophilic Interactions Research Paper Developmental Biology |
| Zdroj: | International Journal of Biological Sciences |
| ISSN: | 1449-2288 |
| DOI: | 10.7150/ijbs.12528 |
| Popis: | Odorant binding proteins (OBPs) transport hydrophobic odor molecules across the sensillar lymph to trigger a neuronal response. Herein, the Minus-C OBP (DhelOBP21) was characterized from Dastarcus helophoroides, the most important natural parasitic enemy insect that targets Monochamus alternatus. Homology modeling and molecular docking were conducted on the interaction between DhelOBP21 and 17 volatile molecules (including volatiles from pine bark, the larva of M. alternatus, and the faeces of the larva). The predicted three-dimensional structure showed only two disulfide bridges and a hydrophobic binding cavity with a short C-terminus. Ligand-binding experiments using N-phenylnaphthylamine (1-NPN) as a fluorescent probe showed that DhelOBP21 exhibited better binding affinities against those ligands with a molecular volume between 100 and 125 Å(³) compared with ligands with a molecular volume between 160 and 185 Å(³). Molecules that are too big or too small are not conducive for binding. We mutated the amino acid residues of the binding cavity to increase either hydrophobicity or hydrophilia. Ligand-binding experiments and cyber molecular docking assays indicated that hydrophobic interactions are more significant than hydrogen-bonding interactions. Although hydrogen-bond interactions could be predicted for some binding complexes, the hydrophobic interactions had more influence on binding following hydrophobic changes that affected the cavity. The orientation of ligands affects binding by influencing hydrophobic interactions. The binding process is controlled by multiple factors. This study provides a basis to explore the ligand-binding mechanisms of Minus-C OBP. |
| Databáze: | OpenAIRE |
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