T7 RNA Polymerase Variants for High mRNA Capping Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mRNA production methods using wild-type RNA polymerase result in low capping rates, leading to waste of raw materials and increased production costs due to the need for column purification of uncapped RNA products, and potential safety concerns with promoter replacement.
Innovation Solution
Development of RNA polymerase variants with specific mutations at amino acid positions (R386, R34, K172, Y178, D388, Q435, N437, or D438) to enhance the capping rate during in-vitro transcription, allowing for higher utilization of cap analogs without requiring promoter replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wild-type RNA polymerase is used for in-vitro transcription, then the transcription process is simple and safe, but the capping rate is low leading to waste of cap analogs and increased production costs
Solution Approach 1:
The patent applies parameter changes by mutating specific amino acid residues in the RNA polymerase enzyme (such as R386, R34, K172, Y178, D388, Q435, N437, or D438 positions) to alter its catalytic properties. These parameter changes in the enzyme's structure enable it to achieve high capping rates (≥90%) while maintaining compatibility with the wild-type promoter sequence, thereby resolving the contradiction between manufacturing precision and substance loss.
2Ease of manufacture
If cap analogs are used with wild-type promoter, then the production process is simple, but the capping rate remains low requiring column purification
Solution Approach 1:
The patent modifies the RNA polymerase enzyme parameters (amino acid sequence) rather than changing the promoter sequence, thereby maintaining the simplicity of the production process while achieving high capping rates. This approach avoids the need for promoter replacement and subsequent column purification steps.
3Manufacturing precision
If promoter replacement is performed to increase capping rate, then the capping rate may improve, but safety concerns and new impurities are generated
Solution Approach 1:
The patent applies parameter changes to the RNA polymerase enzyme instead of modifying the promoter sequence, thereby achieving high capping rates without altering the genetic template. This approach maintains production safety and avoids generating new impurities that would arise from promoter replacement.
Solution Approach 2:
The modified RNA polymerase acts as an intermediary that bridges the gap between the wild-type promoter and high capping efficiency. The enzyme modification enables it to facilitate cap analog incorporation at high rates while leaving the promoter sequence unchanged, thus avoiding safety issues associated with promoter replacement.
4Device complexity
If wild-type RNA polymerase is used, then no enzyme modification is needed, but uncapped RNA products are wasted and require additional purification
Solution Approach 1:
The patent applies minimal parameter changes (specific amino acid mutations) to the RNA polymerase enzyme to achieve high capping rates. This modest modification complexity results in dramatically improved raw material utilization efficiency, eliminating the waste of uncapped RNA products and reducing purification requirements.
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 RNA polymerase variants increase the capping rate of mRNA products to at least 91-100%, reducing raw material waste and production costs while ensuring safety and efficiency in mRNA production.
Implementation Method 1
The RNA polymerase variants increase the capping rate of mRNA products to at least 91-100%
Data Source
AI summary
The present application provides a class of T7 RNA polymerase variants and the use thereof, wherein the amino acid sequences of the T7 RNA polymerase variants comprise, relative to SEQ ID NO: 1, at least one substitution or deletion at amino acid positions selected from R34, K172, Y178, R386, D388, Q435, N437 or D438. The variants have improved catalytic activity relative to the wild-type T7 RNA polymerase, which can increase the capping rate of mRNA products during in-vitro transcription (co-transcriptional capping). In addition, the present application further provides a method for preparing RNA by using such variants. By adopting the method to prepare RNA molecules, more capped mRNAs can be obtained.