In silico disulfide bond engineering to improve human leptin stability

Abstract

Enhancing the stability of biomolecules is one of the hot topics in industry. In this study, we enhanced the stability of an important protein called LEPTIN. LEPTIN is a hormone secreted by fat cells playing an essential role in body weight and composition, and its deficiency can result in several disorders. The treatment of related LEPTIN dysfunctions is often available in the form of injection. To decrease the cost and the frequency of its applications can be achieved by increasing its lifetime through engineering LEPTIN. In this study, to engineer LEPTIN, we have introduced disulfide bonds. Disulfide By Design server was used to predict the suitable nominate pairs, which suggested three pairs of amino acids to be mutated to cysteine for disulfide bond formation. Additionally, to further evaluate the effect of combined mutations, we combined these three nominated pairs to produce three more mutants. In order to assess the effect of introduced mutations, molecular dynamic (MD) simulation was performed. The result suggests that Mutant-1 is more stable in comparison to wild-type and the other mutants. Moreover, docking results showed that the introduced mutation does not affect the receptor binding performance; therefore, it can be considered a suitable choice for future protein engineering.