Codon-Optimized rhBMP-2 DNA for E. coli Expression Yield
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Solution Overview
Problem
Current methods for producing recombinant human bone morphogenetic protein-2 (rhBMP-2) face challenges such as low yield, high production costs, and instability, limiting its application in bone repair and regeneration, particularly in prokaryotic expression systems like E. coli, where glycosylation is not possible and protein activity is compromised.
Innovation Solution
Optimized DNA sequences for rhBMP-2 are designed based on codon bias in E. coli, enhancing expression levels by up to 50% and incorporating specific codons at positions like the 9th, 23rd, 34th, and 86th amino acids, along with additional residues for improved stability and activity, using engineered cells and optimized expression vectors for efficient secretion and purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional DNA sequences are used for rhBMP-2 expression in E. coli, then the expression can be achieved, but the yield is low and production cost is high
Solution Approach 1:
The patent applies codon optimization by changing the DNA sequence parameters to match E. coli's preferred codon usage patterns. Specifically, the patent modifies rare codons (e.g., AGG, AGA for arginine; CUA, CUG for leucine) to more frequently used codons in E. coli, thereby improving translation efficiency and protein yield without changing the amino acid sequence. This parameter change in the genetic code directly addresses the low yield problem while reducing production costs through higher expression efficiency.
2Ease of manufacture
If prokaryotic expression system is used for rhBMP-2 production, then the production cost is reduced, but the protein activity is compromised due to lack of glycosylation
Solution Approach 1:
The patent extracts and removes the glycosylation sites (N-X-S/T sequences) from the rhBMP-2 protein structure. By eliminating the need for glycosylation through deliberate removal of these sites, the patent enables successful prokaryotic expression in E. coli while maintaining protein stability and activity. This extraction approach resolves the contradiction by making the protein compatible with cost-effective prokaryotic systems without requiring eukaryotic post-translational modifications.
Solution Approach 2:
The patent changes the molecular parameters of rhBMP-2 by removing glycosylation sites and optimizing the amino acid sequence for prokaryotic expression. These parameter changes include eliminating N-linked glycosylation sequences and adjusting the protein structure to enhance stability in the absence of glycosylation, thereby maintaining bioactivity while enabling cost-effective production in E. coli.
3Quantity of substance
If natural BMP-2 is extracted from animal sources, then the protein can be obtained, but the yield is low and purification is difficult due to hydrophobicity and insolubility
Solution Approach 1:
Instead of extracting natural BMP-2 from animal sources, the patent creates a recombinant copy of the BMP-2 gene and expresses it in E. coli. This copying approach produces abundant quantities of the protein through bacterial fermentation, easily overcoming the low yield limitation of animal extraction. The recombinant protein can be purified using standard bacterial protein purification methods, greatly simplifying the manufacturing process compared to extracting hydrophobic natural BMP-2 from animal tissues.
Data Source
AI summary
The invention discloses an optimized DNA sequence of recombinant human bone morphogenetic protein-2 (rhBMP-2) based on the Escherichia coli expression system and a method for the preparation of the rhBMP-2. Specifically, the invention provides the optimal DNA sequences suitable for Escherichia coli expression system, the methods for efficient preparation of the rhBMP-2, and the related construction of the recombinant bacteria, the expression and purification technologies. Compared with the traditional hBMP-2 gene without optimizing, the rhBMP-2 expression level of the optimized gene in Escherichia coli is increased by 50%. Additionally, this invention also provides a method for preparation long chain rhBMP-2 with enhanced renaturation efficiency and yield of purification.