GmolCXEs degraded free ester sex pheromone components in mating
We firstly expressed GmolCXE1 and GmolCXE5 proteins using E. coliTransetta (DE3) cells. Then we purified proteins by Ni ion affinity chromatography (Figure S3). The sex pheromone mixtures were incubated with each purified esterase protein for 1 h before submitted to EAG analysis. As shown in Figure 5, the antennae of male moths had a strong EAG responses to these two ester sex pheromone compounds Z8-12:Ac, E8-12:Ac, and mix (Z8-12:Ac: E8-12:Ac=9:1) under normal conditions. However, after incubated with the purified GmolCXE1 or GmolCXE5 proteins, the EAG amplitudes in response to sex pheromone compounds Z8-12:Ac, E8-12:Ac, and mix were significantly reduced in male moths (Figure 5 A-C).
GC-MS results showed that after Z/E8-12:Ac treated with GmolCXE1 or GmolCXE5, the metabolites Z/E8-12:OH were detected (Figure 6 A-C and E-G). And degradation percentage of Z8-12:Ac were 100% (CXE1) and 35.52% (CXE5) (Figure 6D), and degradation percentage of E8-12:Ac were 64.99% (CXE1) and 33.23% (CXE5) (Figure 6 H).