Bioinformatic analysis of gene encoding odorant binding protein (OBP) 1, OBP2, and chemosensory proteins in Grapholita molesta

In this study, odorant binding proteins (OBPs) and chemosensory protein (CSP), which are associated with the sensitivity of Grapholita molesta, were comprehensively analysed using bioinformatics. The full-length cDNAs of GmolOBP1, GmolOBP2, and GmolCSP were downloaded and their open reading frames (ORFs) were analysed. Their physicochemical properties were determined and their structures and functions were predicted. Additionally, a phylogenetic tree was constructed to investigate the evolutionary relationships among GmolOBP1, GmolOBP2, GmolCSP, and 14 other insect proteins. GmolOBP1, GmolOBP2 and GmolCSP were composed of 164, 161, and 127 amino acids. GmolOBP1 and GmolOBP2 contained 7 and 6 cysteine residues forming 3 disulphide bonds. The transmembrane, hydrophobic, and signal peptide regions overlapped in GmolOBP1 and GmolCSP and were located in the extracellular environment. GmolCSP showed more coiled coils and a smaller cavity in the three-dimensional structure than GmolOBP1 and GmolOBP2. In the phylogenetic tree, GmolOBP1, GmolOBP2, and GmolCSP were in different clusters or sub-clusters. In conclusion, GmolOBP1 and GmolOBP2 shared some common properties with other OBPs. Additionally, GmolOBP1, GmolOBP2, and GmolCSP may have evolved independently.