Modified N-oligosaccharyl Transferase for Broad Substrate Glycosylation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing glycoconjugate vaccines are limited by the efficiency and specificity of N-linked glycosylation processes, particularly in using oligosaccharyl transferases, which restrict the range of usable oligosaccharides and polysaccharides for immunogenic carrier proteins.
Innovation Solution
Development of recombinant N-oligosaccharyl transferases with modified substrate specificities, such as PglB Cj, that can link oligosaccharides or polysaccharides lacking an N-acetyl sugar at the reducing end to carrier proteins, enhancing glycosylation yield and rate by specific amino acid modifications within the enzyme.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional N-oligosaccharyl transferases are used for glycosylation, then the process is simple and straightforward, but the substrate specificity is limited and the range of usable oligosaccharides is restricted
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the N-oligosaccharyl transferase enzyme structure. Mutations at positions such as N311, S80, and N311V alter the enzyme's substrate binding properties, enabling it to accept oligosaccharides lacking N-acetyl sugars at the reducing end, thereby expanding substrate specificity without fundamentally changing the enzyme's core function
Solution Approach 2:
The invention implements local quality changes by introducing site-specific amino acid modifications in the enzyme's substrate binding region. These localized changes at specific residues (e.g., N311V, S80R) modify the chemical properties of the binding pocket to accommodate a broader range of oligosaccharide substrates while leaving the rest of the enzyme structure intact
2Productivity
If wild-type N-oligosaccharyl transferases are used, then the enzyme structure is simple and stable, but the glycosylation yield and rate are limited
Solution Approach 1:
The patent improves productivity by changing the amino acid parameters at key positions in the enzyme. Mutations such as N311V and S80R alter the enzyme's catalytic efficiency and substrate binding affinity, resulting in significantly enhanced glycosylation yields and reaction rates compared to the wild-type enzyme
Solution Approach 2:
The invention applies preliminary action by pre-modifying the enzyme structure through site-directed mutagenesis before the glycosylation reaction. The amino acid substitutions are introduced in advance to optimize the enzyme's catalytic properties, ensuring high productivity from the outset rather than attempting to improve yield during the reaction process
3Adaptability or versatility
If N-oligosaccharyl transferases with modified substrate specificities are developed, then the range of oligosaccharides that can be used is expanded, but the enzyme development process becomes more complex
Solution Approach 1:
The patent achieves expanded adaptability through controlled parameter changes in the enzyme's amino acid sequence. By modifying specific residues (e.g., N311, S80, N311V) rather than performing comprehensive enzyme redesign, the invention broadens the range of acceptable oligosaccharide substrates while maintaining a relatively simple and straightforward enzyme production process
Solution Approach 2:
The invention maintains ease of manufacture by applying local quality modifications only where necessary for substrate recognition. The site-specific mutations in the substrate binding region are sufficient to expand oligosaccharide compatibility without requiring complex global restructuring of the enzyme, thereby preserving relatively simple manufacturing protocols
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
The modified recombinant N-oligosaccharyl transferases significantly increase the yield and rate of glycosylation of carrier proteins, allowing for the production of glycosylated proteins at levels up to 100-fold above background, with specific modifications like N311V and S80R enhancing substrate utilization.
Implementation Method 1
recombinant N-oligosaccharyl transferases with modified substrate specificities, such as PglB Cj, that can link oligosaccharides or polysaccharides lacking an N-acetyl sugar at the reducing end to carrier proteins
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Described herein are oligosaccharyl transferases for use in N-glycosylating proteins of interest in vitro and in host cells. Methods for using such oligosaccharyl transferases, nucleic acids encoding such oligosaccharyl transferases, and host cells comprising such oligosaccharyl transferases are also provided herein. Glycoconjugates generated by using such oligosaccharyl transferases are also provided herein.