The kinetic mechanism of cations induced protein nanotubes self-assembly and their application as delivery system. (July 2022)

• Record Type: Journal Article
• Authors: Zhang, Jipeng; Wang, Qimeng; Liu, Bin; Li, Dan; Zhang, Huijuan; Wang, Pengjie; Liu, Jinfang; Hou, Guohua; Li, Xin; Yuan, Yu; Li, Zekun; Chen, Shanan; Yan, Huiling; Li, Yuan
• Is Part Of: Biomaterials. Volume 286(2022)
• Publication Date: 2022-07
• Subjects: Self-assembly -- Nanotubes -- Helical structures -- Calcium coordination -- α-Lactalbumin; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2022.121600
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: The amphiphilic proteins can be used as building blocks (BBs) forming various self-assemblies. Understanding their self-assembly mechanism is important for designing novel nanomaterials. Herein, the BBs dimers were first prepared from carboxyl-abundant enzymolyzed α-lactalbumin (α-lac) at 50 °C. Then the unidentate coordination of Ca 2+ between the BBs caused a β-sheet stacking to further self-assemble into nanotubes (NTs). Compared with the traditional "one-pot" method, a step-wise new method was applied to study hydrolysis, aggregation and self-assembly processes separately. The α-lac was hydrolyzed into 11 kDa amphiphilic peptides independent of temperature while a BBs dimer was formed at 50 °C by hydrophobic interaction. Ca 2+ induced a conformational change of BBs and promoted these BBs gradually aggregate into 10 strands of filaments, which twisted into helical ribbons by electrostatic repulsion. Ca 2+ further induced the twisted helical ribbons closed into NTs driven by the reduction of line tension energy. Besides, the carboxyl-Ca 2+ coordination dominated NTs elongation in the longitudinal direction and filaments aggregation in the lateral direction with the same binding stoichiometry of 1:1 respectively. Finally, NTs successfully encapsulated curcumin and improved the viscosity of liquid food. α-Lac NTs show a high potential as a delivery system for food applications.