环化提高CVB3衣壳蛋白VP1的热稳定性和抗蛋白酶降解能力

VB3 capsid protein-1 (VP1) is an immunodominant structural protein that plays an important role in eliciting of host immune response. However, the termini of linear proteins are often flexible and easily become the targets of proteolytic enzymes. An alternative way to overcome the limitations of linear protein is the cyclization of the polypeptide backbone. It has been shown that circular proteins can increase their thermostability and resistance to chemical, thermal, or enzymatic degradation due to lacking of both amino and carboxyl termini. In this study, we have joined the N- and C-termini of VP1 protein with a normal peptide bond using intein-mediated protein trans-splicing, which produced the VP1 protein with a circular topology. Successful cyclization was proven by relinearization by proteolytic cleavage and by resistance against carboxypeptidase. The circular form of VP1 was found to be significantly more stable against irreversible aggregation upon heating than the linear form.