Purification and characterisation of sarcoplasmic calcium-binding protein, a novel allergen of red swamp crayfish (Procambarus clarkii)

摘要

College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety.Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China;%Crayfish sarcoplasmic calcium-binding protein (SCP) was purified. The physicochemical and polymorphic characterisations were also analysed. SCP was purified by column chromatography to reveal a single band with molecular mass of 22 kDa and further confirmed by mass spectrometry. The results of physicochemical characterisation showed that SCP was stable in the processes of thermal or acid/alkali treatment, and could be digested by simulate gastrointestinal fluid. Importantly, the comparison of SCP polymorphism using sera from crustacean-allergic patients demonstrated SCP-II had a weaker lgE-binding activity. The isoelectric points of SCP subunits a, b and c were 4.6, 4.7, and 4.8, respectively, as determined by two-dimensional electrophoresis and IgE immunoblotting analysis showed that patients' sera reacted to three subunits of SCP. Finally, it can be concluded that SCP is a stable polymorphic allergen in crayfish, and all of its isotypes and subunits have allergenicity.