Abstract: Odorant-binding proteins (OBPs) are responsible for physiological function via perception of volatile odors. Here we reported the successful expression and purification of a general odorant binding protein Lsti-GOBP1 from Loxostege sticticalis L. Lsti-GOBP1 was expressed using Escherichia coli Rosetta (DE3) prokaryotic expression system, and then purified using Histrap HP column, and the protein functions of Lsti-GOBP1 were tested by fluorescent probe N-phenyl-1-naphthylamine (1-NPN) binding assays and competitive binding assays with 50 kinds of chemical molecules. The results showed that Lsti-GOBP1 had the capability of binding 35 odorants. However, only 1-hexanol, 1-heptanol, cinnamaldehyde and camphene replaced 1-NPN from Lsti-GOBP1 by 50%, and their binding constants were 8.997, 7.283, 7.289 and 9.814 μmol/L, respectively. So, it can be speculated that Lsti-GOBP1 has a wide binding characteristics, but it has strong binding specificity to 1-hexanol, 1-heptanol, cinnamaldehyde and camphene, which probably all play a critical role in the process of recognizing different odorants in L. sticticalis.

Key words: Loxostege sticticalis, general odorant binding protein Ⅰ(GOBP1) , protein expression , purification , N-phenyl-1-naphthylamine , fluorescent binding assay