A General Thermostabilization Strategy Based on Self-assembling Amphipathic Peptides for Fusion Tags

Publication date: Available online 17 November 2018Source: Enzyme and Microbial TechnologyAuthor(s): Weixin Zhao, Liming Liu, Guocheng Du, Song LiuAbstractSelf-assembling amphipathic peptides (SAPs) have been used as stabilization tags to improve enzyme stability but do not function uniformly well with all target enzymes. Here, the key factors that involved in SAPs stabilization were identified as the SAP length and linker length and flexibility, using S1 (AEAEAKAK)2 as an originated SAP and polygalacturonate lyase (PGL) as model protein. Biochemical analysis demonstrated that SAPs could induce the loose protein oligomerization formation via intermolecular hydrophobic interactions. Based on the stabilization mechanism, a comprehensive protein modification strategy was proposed, in which a library of stabilizing tags through random combination of different SAPs and linker peptides was developed to optimize the fusion composition while the sodium chloride were used to enhance the intermolecular hydrophobic interactions. The engineered PGL, lipoxygenase (LOX) and L-asparaginase (L-ASN) exhibited remarkably improved thermal stabilities, exhibiting 33.25-, 17.55- and 15.6-fold increases, respectively, in the t1/2 value relative to that of the corresponding wild-type enzyme. The SAPs therefore shows great potential as a fusion method to enhance the enzymes/proteins thermal stability.
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research