Microbial Synthesis of High-Molecular-Weight, Highly Repetitive Protein Polymers

Abstract

High molecular weight (MW), highly repetitive protein polymers are attractive candidates to replace petroleum-derived materials as these protein-based materials (PBMs) are renewable, biodegradable, and have outstanding mechanical properties. However, their high MW and highly repetitive sequence features make them difficult to synthesize in fast-growing microbial cells in sufficient amounts for real applications. To overcome this challenge, various methods were developed to synthesize repetitive PBMs. Here, we review recent strategies in the construction of repetitive genes, expression of repetitive proteins from circular mRNAs, and synthesis of repetitive proteins by ligation and protein polymerization. We discuss the advantages and limitations of each method and highlight future directions that will lead to scalable production of highly repetitive PBMs for a wide range of applications.

Blending recombinant amyloid silk proteins generates composite fibers with tunable mechanical properties

“…7,8 Despite the challenges posed by their repetitive sequences and biased amino acid compositions, recent advances in synthetic biology have overcome many obstacles in the heterologous synthesis of mechanically robust PBMs. 9–11 Several microbially produced PBMs have displayed mechanical performances comparable to or even higher than their natural counterparts. 12–15…”

Genetically Engineered Protein-Based Bioadhesives with Programmable Material Properties

“…1,3,16−18 Additionally, recombinant proteins synthesized from DNA templates allow their protein sequences to be precisely controlled, enabling finetuning of mechanical and adhesive properties to match specific requirements for biomedical applications. 8,17,19,20 These features are hardly achieved by other materials.…”

“…that match the target tissue. Several types of commercial bioglues have been recently developed, including cyanoacrylates, polyester-based adhesives, and poly­(acrylic acid)-based glues. − Most bioglues are synthetic polymers with limited biodegradability, high toxicity, and lack of tunability. − Furthermore, many existing bioglues do not have desirable adhesion to wet biological tissues, thus limiting their practical use. ,, A class of bioglues that has not been extensively explored are those that are completely made of proteins. , Protein-based adhesives are generally biocompatible and bioabsorbable as many protein-based biomaterials have been used for biomedical applications. ,,− Additionally, recombinant proteins synthesized from DNA templates allow their protein sequences to be precisely controlled, enabling fine-tuning of mechanical and adhesive properties to match specific requirements for biomedical applications. ,,, These features are hardly achieved by other materials.…”

Designed Multifunctional Spider Silk Enabled by Genetically Encoded Click Chemistry

“…[ 12 ] It provides selective and efficient ligation between protein molecules, at their N‐, C‐terminal, or even middle regions, distinguishing it from other methods such as sortase ligation and split intein that mediate protein ligations invariably from N‐ to C‐terminal. [ 13 ] Given its proven robustness and versatility, Spy chemistry offers a simple and modular approach to functionalize recombinant spider silk.…”

“…An alternative approach is to produce recombinant spider silk protein (spidroin) in heterologous hosts from N-to C-terminal. [13] Given its proven robustness and versatility, Spy chemistry offers a simple and modular approach to functionalize recombinant spider silk.…”