Enhanced molecular stability of ApxII antigen during secretion in Corynebacterium glutamicum by rational design.

ApxII is a vaccine antigen used to protect against porcine contagious pleuropneumonia, which is a significant threat to the pig industry. Here, we aimed to improve the proteolytic degradation stability of ApxII during its secretion by establishing a complete screening process of stable variants through bioinformatics and site-directed mutagenesis. We employed a combination of semi-rational and rational design strategies to create 34 single-point variants of ApxII.