Recombinant Silk and Collagen Secretion via E. Coli Curli
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing spider silk and bacterial collagen face challenges such as the difficulty in domesticating spiders for large-scale silk production due to their venomous and cannibalistic nature, and the complexity and cost of intracellular production and purification of recombinant proteins, which limits their scalability and efficiency.
Innovation Solution
Utilizing a bacterial secretion system, specifically the curli pathway in E. coli, to extracellularly produce and purify silk and collagen proteins by engineering bacteria to express recombinant proteins with periplasmic and outer membrane signal sequences, enabling secretion and simplifying purification through enzymatic digestion, size-based separation, and acid precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spiders are used for silk production, then silk quality and strength are improved, but domestication difficulty and production scalability worsen due to venomous and cannibalistic nature
Solution Approach 1:
The patent copies the silk protein sequence from spider silk genes and expresses it in bacterial systems (E. coli, B. subtilis). Instead of using actual spiders, the invention creates recombinant silk proteins that replicate the functional properties of natural spider silk through bacterial fermentation and secretion systems, thereby avoiding the domestication problems while maintaining silk quality.
2Quantity of substance
If intracellular production methods are used for recombinant proteins, then protein production is achieved, but purification complexity and cost increase
Solution Approach 1:
The patent extracts the recombinant protein directly from the bacterial periplasmic space or extracellular environment rather than from intracellular compartments. By using signal sequences (Sec, Tat, SRP) that direct proteins to the periplasm or extracellular space, the invention simplifies purification by avoiding cell lysis and intracellular contamination, reducing both complexity and cost while maintaining high production quantities.
3Ease of manufacture
If extracellular secretion systems are used, then purification is simplified, but secretion efficiency and protein yield may be reduced
Solution Approach 1:
The patent uses the bacterial periplasm as an intermediary compartment between the cytoplasm and extracellular environment. Signal sequences (Sec, Tat, SRP) mediate protein translocation to the periplasm, where proteins can accumulate at high concentrations before being secreted. This intermediary system maintains high productivity while enabling simplified purification, as the periplasmic space naturally concentrates proteins and separates them from cytoplasmic contaminants.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for the robust production and simplified purification of recombinant silk and collagen proteins, facilitating their scalable manufacturing and utilization in biomaterials and tissue engineering applications.
Implementation Method 1
The nonnative recombinant protein comprises a periplasmic translocation signal sequence, an outer membrane secretion signal sequence, and one or more silk fibroin domains or collagen domains
Implementation Method 2
engineered bacteria to express recombinant proteins with periplasmic and outer membrane signal sequences, enabling secretion
Implementation Method 3
simplifying purification through enzymatic digestion, size-based separation, and acid precipitation
Implementation Method 4
simplifying purification through enzymatic digestion, size-based separation, and acid precipitation
Data Source
AI summary
Disclosed are methods of making recombinant secretion of silk and collagen proteins, and amyloid fusions thereof, using bacteria.