Engineered Reverse Transcriptases for Thermostable Low-Volume cDNA Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Challenges in cDNA synthesis include interference from RNA secondary structures and reduced enzyme activity at higher temperatures, as well as inhibition by cell lysates and low reaction volumes, which affect the efficiency of wild-type Moloney Murine Leukemia Virus (MMLV) reverse-transcriptase, particularly in low volume reactions.
Innovation Solution
Development of engineered reverse transcriptases with specific mutations, such as M39V, M66L, E69K, E302R, T306K, W313F, L435G, and N454K, to enhance thermostability and activity in low volume reactions, improving transcription efficiency and template switching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If higher reaction temperature is used to remove RNA secondary structure, then RNA secondary structure interference is reduced, but reverse-transcriptase enzyme activity decreases
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence of the reverse-transcriptase enzyme through specific mutations (M39V, M66L, E69K, E302R, T306K, W313F, L435G, N454K) to alter the enzyme's thermostability parameters. These mutations enable the enzyme to maintain stable activity at higher temperatures (50-65°C) where wild-type enzyme would be inactivated, thus resolving the contradiction between removing RNA secondary structure and maintaining enzyme activity.
2Volume of stationary object
If wild-type MMLV reverse-transcriptase is used in low volume reactions, then reaction volume is reduced, but enzyme activity is negatively impacted
Solution Approach 1:
The patent uses parameter changes by introducing specific amino acid mutations that alter the enzyme's physical and chemical properties to improve its performance in low volume conditions. The mutated enzyme maintains high activity in reactions with volumes less than 1 nL, overcoming the limitation of wild-type enzyme which shows reduced activity in such low volume conditions.
3Adaptability or versatility
If wild-type MMLV reverse-transcriptase is used, then standard conditions are maintained, but thermostability is insufficient
Solution Approach 1:
The patent applies parameter changes through site-directed mutagenesis at specific positions (M39V, M66L, E69K, E302R, T306K, W313F, L435G, N454K) to enhance the enzyme's thermostability parameter while preserving its fundamental reverse-transcriptase function. The mutated enzyme maintains compatibility with standard reaction conditions while exhibiting improved stability at elevated temperatures compared to wild-type.
Data Source
AI summary
The application provides compositions including engineered reverse transcriptases with at least one altered reverse-transcriptase related activity. The engineered reverse transcriptases or reverse transcription enzymes unexpectedly exhibit one or more altered reverse transcriptase related activities such as but not limited to altered template switching efficiency, altered transcription efficiency or both.