Solution Structure of a Chemosensory Protein from the Desert Locust Schistocerca gregaria
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- 作者：Simona Tomaselli ; Orlando Crescenzi ; Domenico Sanfelice ; Eiso AB ; Rainer Wechselberger ; Sergio Angeli ; Andrea Scaloni ; Rolf Boelens ; Teodorico Tancredi ; Paolo Pelosi ; Delia Picone
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：September 5, 2006
- 年：2006
- 卷：45
- 期：35
- 页码：10606 - 10613
- 全文大小：437K
- 年卷期：v.45,no.35(September 5, 2006)
- ISSN：1520-4995
文摘
Chemical stimuli, generally constituted by small volatile organic molecules, are extremelyimportant for the survival of different insect species. In the course of evolution, insects have developedvery sophisticated biochemical systems for the binding and the delivery of specific semiochemicals totheir cognate membrane-bound receptors. Chemosensory proteins (CSPs) are a class of small solubleproteins present at high concentration in insect chemosensory organs; they are supposed to be involvedin carrying the chemical messages from the environment to the chemosensory receptors. In this paper, wereport on the solution structure of CSPsg4, a chemosensory protein from the desert locust Schistocercagregaria, which is expressed in the antennae and other chemosensory organs. The 3D NMR structurerevealed an overall fold consisting of six 
-helices, spanning residues 13-18, 20-31, 40-54, 62-78,80-90, and 97-103, connected by loops which in some cases show dihedral angles typical of 
-turns.As in the only other chemosensory protein whose structure has been solved so far, namely, CSP from themoth Mamestra brassicae, four helices are arranged to form a V-shaped motif; another helix runs acrossthe two V's, and the last one is packed against the external face. Analysis of the tertiary structure evidencedmultiple hydrophobic cavities which could be involved in ligand binding. In fact, incubation of the proteinwith a natural ligand, namely, oleamide, produced substantial changes to the NMR spectra, suggestingextensive conformational transitions upon ligand binding.
-helices, spanning residues 13-18, 20-31, 40-54, 62-78,80-90, and 97-103, connected by loops which in some cases show dihedral angles typical of -turns.As in the only other chemosensory protein whose structure has been solved so far, namely, CSP from themoth Mamestra brassicae, four helices are arranged to form a V-shaped motif; another helix runs acrossthe two V's, and the last one is packed against the external face. Analysis of the tertiary structure evidencedmultiple hydrophobic cavities which could be involved in ligand binding. In fact, incubation of the proteinwith a natural ligand, namely, oleamide, produced substantial changes to the NMR spectra, suggestingextensive conformational transitions upon ligand binding.