Antibody drugs will cause side effects due to they can＇t distinguish disease region from normal region. We used hinge domain as antibody lock, which is linked to antibody by protease substrate, to generate a pro-antibody that can block the binding ability. The Ab lock will be removed by the protease that is overexpressed in the disease region so that the binding activity will be revived. Antibody lock can increase the selectivity of antibodies and reduce side effects.

1.Hinge can prevent the immune rejection 
2.It masks the antigen binding site of antibody through spatial hindrance to make sure that antibody lock can efficiently release from the pro-antibody after protease cleavage 
3.Computer simulation optimized the blocking efficiency of antibody lock thus antibody lock successfully applied to any antibodies

1. We develop selective-activated "second generation antibody" to reduce side effects and then upgrade the value of antibody 
2. Antibody lock can renew expired patent 
3. Discontinued antibody drug due to severe side effects can be remarketing through antibody lock
    Our antibody lock can be extended to all antibody-derived formats to all antibody companies and revolutionize the development of Ab drugs.