Curli-Mediated Self-Assembly of a Fibrous Protein Scaffold for Hydroxyapatite Mineralization

Zahra Abdali, Masoud Aminzare, Xiaodan Zhu, Elizabeth Debenedictis, Oliver Xie, Sinan Keten, Noémie Manuelle Dorval Courchesne*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Nanostructures formed by self-assembled peptides have been increasingly exploited as functional materials for a wide variety of applications, from biotechnology to energy. However, it is sometimes challenging to assemble free short peptides into functional supramolecular structures, since not all peptides have the ability to self-assemble. Here, we report a self-assembly mechanism for short functional peptides that we derived from a class of fiber-forming amyloid proteins called curli. CsgA, the major subunit of curli fibers, is a self-assembling β-helical subunit composed of five pseudorepeats (R1-R5). We first deleted the internal repeats (R2, R3, R4), known to be less essential for the aggregation of CsgA monomers into fibers, forming a truncated CsgA variant (R1/R5). As a proof-of-concept to introduce functionality in the fibers, we then genetically substituted the internal repeats by a hydroxyapatite (HAP)-binding peptide, resulting in a R1/HAP/R5 construct. Our method thus utilizes the R1/R5-driven self-assembly mechanism to assemble the HAP-binding peptide and form hydrogel-like materials in macroscopic quantities suitable for biomineralization. We confirmed the expression and fibrillar morphology of the truncated and HAP-containing curli-like amyloid fibers. X-ray diffraction and TEM showed the functionality of the HAP-binding peptide for mineralization and formation of nanocrystalline HAP. Overall, we show that fusion to the R1 and R5 repeats of CsgA enables the self-assembly of functional peptides into micron long fibers. Further, the mineral-templating ability that the R1/HAP/R5 fibers possesses opens up broader applications for curli proteins in the tissue engineering and biomaterials fields.

Original languageEnglish (US)
Pages (from-to)3334-3343
Number of pages10
JournalACS synthetic biology
Volume9
Issue number12
DOIs
StatePublished - Dec 18 2020

Keywords

  • biomaterials
  • biomineralization
  • curli fibers
  • hydroxyapatite-binding peptide
  • self-assembling proteins
  • supramolecular protein materials

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)

Fingerprint

Dive into the research topics of 'Curli-Mediated Self-Assembly of a Fibrous Protein Scaffold for Hydroxyapatite Mineralization'. Together they form a unique fingerprint.

Cite this