Three mutated versions of the allergen were expressed in P. pastoris. One of the variants, with mutation H229A, had no detectable phospholipase A1 activity and was secreted by P. pastoris at higher yields than other two forms. Although enzymatically inactive, the protein preserved its IgE binding activity as shown in EAST and inhibition EAST using serum from wasp venom allergic patients, it was also immunological active illustrated by its capability to mediated histamine Paclitaxel release from basophils sensitized with wasp venom specific IgE. The yield of pure recombinant protein was 1.7 mg/L fermentation broth. The yield can be further enhanced by strain improvement, where either a rational approach can be undertaken with optimization of promoter, signal sequence, copy number in the genome or a simple GDC-0879 Raf inhibitor screening of a larger number of clones can be carried out. The fact that expression of Ves v 1 was higher at lower temperature indicates possible limited capacity of the cells to properly fold the given protein. If this is the case, usage of a weaker promoter could be an advantage as this would prevent the occurrence of the unfolded protein response. Furthermore fermentation can be optimized, where high cell-density cultivations can routinely give order of magnitude higher yields than shake flask cultures. In conclusion, we established expression of an enzymatically inactive wasp venom allergen rVes v 1 in methylotrophic yeast P. pastoris. The protein had histidine 229 in the enzyme active site replaced by alanine. The protein showed immunological activity in EAST and histamine release assay and could inhibit the binding of Ves v 1-reactive sera to wasp venom. It presents a candidate of recombinant immunotherapy, particularly in combination with another major wasp venom allergen rVes v 5, which has also been produced in P. pastoris. The increased rate of metabolic diseases, such as obesity, diabetes and cardiovascular disease, has become a major public health concern . The common characteristic of human obesity and type 2 diabetes is insulin resistance . Liver plays a critical role in mediating glucose and lipid homeostasis regulated by hormones and nutrients. Factors derived from adipose tissues, such as free fatty acid , adipokines and inflammatory cytokines have been proposed to be responsible for the hepatic insulin resistance.