De novo rational design of a freestanding, supercharged polypeptide, proton-conducting membrane

Chao Ma, Jingjin Dong, Marco Viviani, Isotta Tulini, Nicola Pontillo, Sourav Maity, Yu Zhou, Wouter H. Roos, Kai Liu, Andreas Herrmann, Giuseppe Portale*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)
48 Downloads (Pure)

Abstract

Proton translocation enables important processes in nature and man-made technologies. However, controlling proton conduction and fabrication of devices exploiting biomaterials remains a challenge. Even more difficult is the design of protein-based bulk materials without any functional starting scaffold for further optimization. Here, we show the rational design of proton-conducting, protein materials exceeding reported proteinaceous systems. The carboxylic acid-rich structures were evolved step by step by exploring various sequences from intrinsically disordered coils over supercharged nanobarrels to hierarchically spider β sheet containing protein-supercharged polypeptide chimeras. The latter material is characterized by interconnected β sheet nanodomains decorated on their surface by carboxylic acid groups, forming self-supportive membranes and allowing for proton conduction in the hydrated state. The membranes showed an extraordinary proton conductivity of 18.5 ± 5 mS/cm at RH = 90%, one magnitude higher than other protein devices. This design paradigm offers great potential for bioprotonic device fabrication interfacing artificial and biological systems.

Original languageEnglish
Article number0810
Number of pages9
JournalScience Advances
Volume6
Issue number29
DOIs
Publication statusPublished - Jul-2020

Keywords

  • SPIDER SILK
  • GROTTHUSS
  • EVOLUTION
  • TRANSPORT
  • PROTEINS
  • WATER

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