Eukaryotic Expression of the Cytochrome c Oxidase Subunit I of Sitophilus zeamais and Its Interaction with Allyl Isothiocyanate.

Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) is a destructive pest of stored grains around the world. Allyl isothiocyanate (AITC) was shown to have good bioactivity in the control of S. zeamais . In this study, the interaction of AITC on cytochrome c oxidase core subunits I (COX I) and their binding mechanism were determined using spectroscopic, isothermal titration calorimetry and molecular docking techniques. The results indicate the binding constant ( K a ) of AITC and COX I was 6.742 × 10 3 L/mol. Analysis of spectroscopic revealed that the binding of COX I to reduced Cyt c induced conformational changes of reduced Cyt c, while AITC could competitively bind and inhibit the activity of the COX I protein. Moreover, molecular docking results suggested a sulfur atom in the AITC structure could form a hydrogen bond having a length of 3.3 Å with the Gly- 27 of COX I.