| Autor: |
Jing X; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Zhu Z; Changping Laboratory, Beijing 102200, China., Wang S; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Xin J; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Zhou H; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Wang L; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Tong H; Department of Instrument Analysis Center of Xi'an Jiaotong University, Xi'an 710049, China., Cui C; Department of Instrument Analysis Center of Xi'an Jiaotong University, Xi'an 710049, China., Zhang Y; Department of Applied Chemistry, School of Science, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter (Xi'an Jiaotong University), Xi'an Key Laboratory of Sustainable Energy Materials Chemistry and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China., Sun F; Department of Chemical and Biological Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China., Yang L; Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China., Gao Y; Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.; Changping Laboratory, Beijing 102200, China., Lu H; Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China. |
| Abstrakt: |
The secondary structures of polypeptides, such as an α-helix and a β-sheet, often impart specific properties and functions, making the regulation of their secondary structures of great significance. Particularly, water-soluble polypeptides bearing a β-sheet conformation are rare and challenging to achieve. Here, a series of oligo(ethylene glycol)-modified lysine N -carboxylic anhydrides ( EG m K-NCA, where m = 1-3) and the corresponding polymers EG m K n are synthesized, with urethane bonds as the linker between the side-chain EG and lysine. The secondary structure of EG m K n is delicately regulated by both m and n , the length (number of repeating units) of EG and the degree of polymerization (DP), respectively. Among them, EG2 K n adopts a β-sheet conformation with good water solubility at an appropriate DP and forms physically cross-linked hydrogels at a concentration as low as 1 wt %. The secondary structures of EG1 K n can be tuned by DP, exhibiting either a β-sheet or an α-helix, whereas EG3 K n appears to a adopt pure and stable α-helix with no dependence on DP. Compared to previous works reporting EG-modified lysine-derived polypeptides bearing exclusively an α-helix conformation, this work highlights the important and unexpected role of the urethane connecting unit and provides useful case studies for understanding the secondary structure of polypeptides. |
