Title
Recurring sequence-structure motifs in (βα)8-barrel proteins and experimental optimization of a chimeric protein designed based on such motifs
Author
Jichao Wang, Tongchuan Zhang, Ruicun Liu, Meilin Song, Juncheng Wang, Jiong Hong, Quan Chen, Haiyan Liu
Year
2016
Journal
Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics
Abstract
An interesting way of generating novel artificial proteins is to combine sequence motifs from natural proteins, mimicking the evolutionary path suggested by natural proteins comprising recurring motifs. We analyzed the βα and αβ modules of TIM barrel proteins by structure alignment-based sequence clustering. A number of preferred motifs were identified. A chimeric TIM was designed by using recurring elements as mutually compatible interfaces. The foldability of the designed TIM protein was then significantly improved by six rounds of directed evolution. The melting temperature has been improved by more than 20 °C. A variety of characteristics suggested that the resulting protein is well-folded. Our analysis provided a library of peptide motifs that is potentially useful for different protein engineering studies. The protein engineering strategy of using recurring motifs as interfaces to connect partial natural proteins may be applied to other protein folds.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Protein denaturation, Chemical stability, Biochemistry