Year: 2023
Type: article
Abstract: Protein-based biomaterials have played a key role in tissue engineering, and additional exciting applications as self-healing materials and sustainable polymers are emerging. Over the past few decades, recombinant expression and production of various fibrous proteins from microbes have been demonstrated; however, the resulting proteins typically must then be purified and processed by humans to form usable fibers and materials. Here, we show that the Gram-positive bacterium Bacillus subtilis can be programmed to secrete silk through its translocon via an orthogonal signal peptide/peptidase pair. Surprisingly, we discover that this translocation mechanism drives the silk proteins to assemble into fibers spontaneously on the cell surface, in a process we call secretion-catalyzed assembly (SCA). Secreted silk fibers form self-healing hydrogels with minimal processing. Alternatively, the fibers retained on the membrane provide a facile route to create engineered living materials from Bacillus cells. This work provides a blueprint to achieve autonomous assembly of protein biomaterials in useful morphologies directly from microbial factories.
Institution: Johns Hopkins University
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: CAREER: Leaving the Fold: Leveraging Mass Spectrometry Proteomics to Shift the Paradigm on Protein Folding, G2434405027, G438544789, Mechanisms of Protein Self-Assembly Coupled to Membrane Mechanics in the Cell., Watching Proteins Fold (or Misfold) in vivo with Mass Spectrometry, G6671297155
OpenAlex ID: W4384820527