Purification, Expression, and Characterization of Sarcoplasmic Calcium Binding Protein: A Novel Allergen of Portunus trituberculatus .

Swimming crab (), a crucial valuable crustacean, is a common factor causing food allergy. However, studies on allergens of are scarce. In this study, the sarcoplasmic calcium binding protein (SCP) of was expressed in , purified with affinity chromatography, and the IgE-binding activity was evaluated through serological analyses. Further, the structure, physicochemical properties, and cross-reactivity were assessed via bioinformatics, immunologic, and spectroscopy techniques. The results indicated that SCP was an allergen displaying strong IgE-binding capacity, composed of 60% α-helix. It presented good immunologic and structural stability at 4-70 °C and pH 3-10, and only exhibited high IgG cross-reactivity among crustaceans, without cross-reactivity with other species tested. These results establish the foundations for further studies on SCP and are promising to promote the development of specific crustacean allergen detection and precise allergy diagnosis.