Molecular characterization of the allergenic Arginine Kinase from the edible insect Hermetia illucens (black soldier fly)

Arginine kinase (AK) is an important enzyme for energy metabolism of invertebrate cells by participating in the maintenance of constant levels of ATP. However, AK is also recognized as a major allergen in insects and crustaceans capable of cross-reactivity with sera of patients sensitized to orthologous proteins. In the perspective of introducing insects or their derivatives in the human diet in Western world, it is of primary importance to evaluate possible risks for allergic consumers. In this work we reported the identification and characterization of AK from Hermetia illucens commonly known as the black soldier fly, a promising insect for human consumption. To evaluate allergenicity of AK from H. illucens, putative linear and conformational epitopes were identified by bioinformatics analyses, and Dot-Blot assays were carried out by using sera of patients allergic to shrimp or mites to validate the cross-reactivity. Gastrointestinal digestion reduced significantly the linear epitopes resulting in lower allergenicity, while the secondary structure was altered at increasing temperatures supporting the possible loss or reduction of conformational epitopes. Our results indicate +that the possible allergenicity of AK should be taken in consideration when dealing with novel foods containing H. illucens or its derivatives.