title: A Novel Strategy for Thermostability Improvement of Trypsin Based on N-Glycosylation within the Ω-Loop Region.
abstract: The Ω-loop is a nonregular and flexible structure that plays an important role in molecular recognition, protein folding, and thermostability. In the present study, molecular dynamics simulation was carried out to assess the molecular stability and flexibility profile of the porcine trypsin structures. Two Ω-Loops (fragment 57-67 and fragment 78-91) were confirmed to represent the flexible region. Subsequently, glycosylation site-directed mutations (A73S, N84S, and R104S) were introduced within the Ω-loop region and its wing chain based on its potential N-glycosylation sites (Asn-Xaa-Ser/Thr consensus sequences) and structure information to improve the thermostability of trypsin. The result demonstrated that the halflife of the N84S mutant at 50°C increased by 177.89 min when compared with that of the wildtype enzyme. Furthermore, the significant increase in the thermal stability of the N84S mutant has also been proven by an increase in the Tm values determined by circular dichroism. Additionally, the optimum temperatures of the wild-type enzyme and the N84S mutant were 75°C and 80°C, respectively. In conclusion, we obtained the thermostability-improved enzyme N84S mutant, and the strategy used to design this mutant based on its structural information and N-linked glycosylation modification could be applied to engineer other enzymes to meet the needs of the biotechnological industry.
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Guo
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Du
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: Yiru
authors.initials: Y
authors.lastname: Gan
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China.|Key Laboratory of System Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, P.R. China.|Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P.R. China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D004795:Enzyme Stability; D006031:Glycosylation; D006868:Hydrolysis; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D015202:Protein Engineering; D011994:Recombinant Proteins; D013057:Spectrum Analysis; D013329:Structure-Activity Relationship; D013552:Swine; D013816:Thermodynamics; D014357:Trypsin / Q000737:chemistry* / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D014357:Trypsin
keywords: N-glycosylation; thermostability; trypsin; Ω-loop