Preparation, characterization, and potential application of shark derived single domain antibody against myofibrillar binding serine protease in Silver carp

Myofibrillar binding serine protease (MBSP) existing in fish muscle is the leading cause of gel deterioration, which adversely affects the quality of surimi produces. Screening and preparation of protease inhibitors with high efficiency and specificity is an important approach to address the reduction of surimi quality. In this study, shark derived single domain antibody specific to MBSP was expressed and its properties were investigated systematically. The results showed that single domain antibody specific to MBSP could be expressed in soluble using SUMO fusion tagged Escherichia coli expression system with good thermal and pH stability. The enzyme activity inhibition effect in vitro could reach 62.9% at the concentration of 0.1 mg/ml of single domain antibody. When added in silver carp surimi, it could significantly inhibit the deterioration of surimi gel. The results of this study implied that shark derived single domain antibody could be developed as a new inhibitor of MBSP used for the control of gel degradation in surimi produces. Novelty impact statement Shark derived single domain antibody specific to MBSP was expressed in soluble with high yield and stability; the expressed antibody could significantly inhibit the activity of MBSP both in vitro and in surimi; this good characteristic makes it to be an inhibitor for the deterioration of surimi gel.