Increasement of Heterologous Expression of Recombinant Vit v 1 in Pichia pastoris KM71 by Nonionic Detergents as a Cost-effective Approach

Abstract Vit v 1 as a lipid-transfer protein is a major allergen of grapes (Vitis vinifera) that elicits food allergy in many patients in Iran. Todays, recombinant allergens have a promising future in improving in vivo and in vitro diagnostic tests. In this study, we aim to achieve high-level expression of recombinant Vit v 1 allergen in Pichia pastoris expression system. DNA construct has been cloned into the pGAPZαC plasmid and expressed in the methylotrophic yeast P. pastoris KM71. The maximum yield obtained after 4 days of expression under the optimal conditions (at 25°C with 0.05% Triton X-100). The secreted recombinant Vit v 1 was purified by nickel-affinity chromatography. The results showed that the recombinant Vit v 1 was expressed mainly as the soluble protein with an apparent molecular mass of 37.8 kDa in the SDS-PAGE and Western blotting. The findings suggest that nonionic detergents could increase yield of recombinant Vit v 1, probably through enhancing transfer of oxygen and membrane lipids fluidity.