Crystal Structure Analysis of Sarcoplasmic-Calcium-Binding Protein: An Allergen in Scylla paramamosain

The structure of allergenic proteins provides important information about the binding of allergens to antibodies. In this study, the crystal structure of Scy p 4 with a resolution of 1.60 angstrom was obtained by X-ray diffraction. Epitope mapping of Scy p 4 revealed that linear epitopes are located on the surface of Scy p 4. Also, conformational epitopes are mostly located in the structural conservative region. Further structural comparison, surface electrostatic potential, and hydrogen bond force analysis showed that mutation of Asp70 and Asp18/20/70 would lead to calcium-binding capacity being lost and destruction of allergenicity. Furthermore, a comparative analysis of structure showed that sarcoplasmic-calcium-binding protein (SCP) had high sequence, secondary, and spatial structural identity in crustaceans, which may be an important factor leading to cross-reactivity among crustaceans. The structure of Scy p 4 provides a template for epitope evaluation and localization of SCPs, which will help to reveal cross-reactivity among species.

Automated summary

The crystal structure of Scy p 4 was obtained with a resolution of 1.60 angstrom by X-ray diffraction, and it revealed the presence of linear and conformational epitopes. Mutation of Asp70 and Asp18/20/70 resulted in loss of calcium-binding capacity and allergenicity. Comparative analysis showed high structural similarity of sarcoplasmic-calcium-binding protein (SCP) in crustaceans, which may contribute to cross-reactivity. The structure of Scy p 4 provides a template for epitope evaluation and localization of SCPs, aiding in the understanding of cross-reactivity among species.