Engineered Eukaryotic Cells for Homogeneous LacNAc Glycoproteins
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Solution Overview
Problem
Current methods for producing therapeutic glycoproteins in eukaryotic cells result in a mixture of glycoforms with varying glycan structures, making it difficult to achieve a homogeneous galactosylation pattern, particularly with terminal galactose residues, which is desirable for specific conjugation applications.
Innovation Solution
Engineered eukaryotic cells with a GlycoDelete or GlycoDoubleDelete background, lacking the capacity to produce N-glycans with terminal sialic acid residues, are used to produce recombinant proteins with homogeneous amounts of N-glycans consisting predominantly of LacNAc structures. This is achieved by introducing specific exogenous nucleic acid sequences encoding enzymes like endoglucosaminidase and beta-1,4-galactosyltransferase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional eukaryotic cell systems are used to produce therapeutic glycoproteins, then production capability is achieved, but the glycosylation pattern becomes heterogeneous with varying glycan structures
Solution Approach 1:
The patent removes specific glycosylation enzymes (sialyltransferases, complex N-glycan processing enzymes) from the eukaryotic cell system to eliminate unwanted glycan modifications. By taking out these specific enzymatic functions, the system produces only simplified, homogeneous LacNAc-type glycans without the complexity of native eukaryotic glycosylation pathways.
Solution Approach 2:
The patent fundamentally changes the glycosylation parameters of the cell system by knocking out specific genes encoding glycosylation enzymes. This genetic modification alters the cell's metabolic pathway to produce a restricted, homogeneous glycan profile (LacNAc structures) instead of the diverse native glycosylation pattern.
2Manufacturing precision
If mammalian cell systems are used to produce glycoproteins, then human-like complex glycans are generated, but terminal galactose residues are sialylated reducing homogeneity
Solution Approach 1:
The patent applies preliminary anti-action by preventing sialylation before it can occur. Through genetic knockout of sialyltransferase genes, the system blocks the addition of sialic acid to terminal galactose residues, ensuring that galactose remains exposed and homogeneous without being subsequently modified by sialylation.
Solution Approach 2:
The patent converts the potential harm of incomplete glycosylation (which would normally be considered a defect) into a benefit. By restricting glycosylation to only LacNAc structures, the system achieves homogeneous terminal galactose exposure, which is precisely what is needed for consistent conjugation reactions, rather than the heterogeneous sialylated glycans produced by wild-type mammalian cells.
3Productivity
If glycoproteins with terminal galactose residues are produced for conjugation, then specific coupling is enabled, but heterogeneity in glycan structures reduces conjugation efficiency
Solution Approach 1:
The patent achieves homogeneity by engineering the cell system to produce only a single type of glycan structure (LacNAc) with exposed terminal galactose residues. This uniform glycan profile ensures that all glycoprotein molecules present identical coupling sites, maximizing conjugation efficiency and producing consistent product quality.
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 approach results in recombinant proteins with a high and homogeneous degree of terminal galactosylated glycans, facilitating efficient glycan-specific conjugation and ensuring the homogeneity of glycoprotein conjugates.
Implementation Method 1
a first exogenous nucleic acid sequence encoding an endoglucosaminidase enzyme
Implementation Method 2
a second exogenous nucleic acid sequence encoding a beta-1,4-galactosyltransferase enzyme
Implementation Method 3
galactose can be selectively oxidized at the C6 position using Galactose Oxidase (GAO), yielding a free aldehyde group
Data Source
AI summary
The present invention provides means and methods for the production in eukaryotic cells of homogeneous forms of small glycan structures which carry terminal galactose residues. In addition, the invention provides glycan-conjugates based on specific coupling with galactose residues present on the recombinant glycoproteins.