Expression and purification of PNGase F protein in yeast and its anti-PRV activity

Pseudorabies virus (Pseudorabiesvirus, PRV) has caused huge economic losses to the global pig industry. In recent years, it has been reported that there are PRV mutants, but the traditional vaccine can not completely prevent or control the infection of PRV, so there is an urgent need to develop new broad-spectrum anti-disease drugs for prevention and treatment. PNGase F from bacteria can catalyze the hydrolysis of oligosaccharides linked to asparagine residues on peptides, so we speculate that PNGase F can inhibit virus infection by removing the glycosylation of virus membrane glycoproteins. In this study, PNGase F protein was highly expressed and purified in Pichia pastoris, and the deglycosylation activity of PNGase F expressed in Pichia pastoris was verified. In vitro, 15 μM could significantly inhibit the proliferation of virus in cells. The results of cytotoxicity test showed that PNGase F was not toxic to many cells. To further evaluate the effect of PNGase F in different stages of virus infection, it was found that PNGase F had significant inhibitory effect on virus adsorption and invasion. In vivo experiments in mice, PNGase F could significantly inhibit the replication of PRV Ea strain in mice and inhibit PRV, reduced brain lesions. Our experiments show that PNGase F expressed by yeast can inhibit PRV infection in vitro and in vitro, and its inhibitory mechanism is preliminarily discussed, which can provide a new reference for the development of broad-spectrum antiviral drugs based on PNGase F.