Enzymatic Peptide Coupling via Ligase in Aqueous Media
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for synthesizing insulinotropic peptides like GLP-1, Liraglutide, and Semaglutide face challenges such as low yield, purity issues, and the use of toxic reagents, especially when attempting enzymatic synthesis in aqueous solutions, where hydrolysis often predominates over coupling, and side-chain protective groups are required to prevent racemization.
Innovation Solution
A method involving enzymatic coupling of specific peptide fragments using a subtilisin BPN' variant or homologue as a ligase, where a peptide C-terminal ester or thioester is coupled with a peptide nucleophile in an aqueous medium, overcoming the limitations of hydrolysis and racemization by optimizing the active site mutations and fragment sequences, allowing high yield and purity without the need for side-chain protective groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If enzymatic coupling is performed in aqueous solution, then the process is more environmentally friendly and avoids toxic reagents, but hydrolysis predominates over coupling reducing synthesis efficiency
Solution Approach 1:
The patent changes the chemical parameters of the aqueous solution including pH control (maintaining pH 6.5-8.5), ionic strength adjustment, and temperature optimization to create conditions that favor enzymatic coupling over hydrolysis. The ligase enzyme operates optimally at specific pH and temperature ranges that promote peptide bond formation while minimizing hydrolytic cleavage.
Solution Approach 2:
The ligase enzyme acts as an intermediary catalyst that facilitates peptide bond formation between the C-terminal ester/thioester of the first fragment and the N-terminal amine of the second fragment. This enzymatic mediation enables coupling in aqueous solution without requiring toxic chemical activating agents, as the enzyme provides a controlled microenvironment for bond formation.
2Productivity
If conventional chemical synthesis methods are used, then coupling efficiency can be maintained, but racemization occurs requiring side-chain protective groups
Solution Approach 1:
The patent replaces conventional chemical synthesis mechanisms with enzymatic catalysis. The ligase enzyme provides stereospecific catalysis that inherently prevents racemization at the alpha-carboxyl group during coupling. This biological catalyst substitution eliminates the need for side-chain protective groups that are required in chemical synthesis to prevent unwanted reactions and racemization.
Solution Approach 2:
The enzymatic system performs multiple functions simultaneously: it activates the C-terminal carboxyl group for coupling, maintains stereochemical integrity, and selectively catalyzes bond formation without requiring external protective groups. The enzyme's active site provides a chiral environment that naturally preserves L-amino acid configuration throughout the coupling process.
3Ease of manufacture
If peptide fragments are coupled using conventional methods, then the process is straightforward, but yield and purity are reduced requiring extensive purification
Solution Approach 1:
The ligase enzyme serves as a selective intermediary that catalyzes only the desired coupling reaction between specific peptide fragments with high efficiency and specificity. This enzymatic selectivity produces the target peptide with high purity and minimal side products, reducing the need for extensive purification steps while maintaining process simplicity.
Solution Approach 2:
The patent optimizes reaction parameters including enzyme concentration, substrate concentration ratios, pH, temperature, and reaction time to maximize coupling yield and product purity. These parameter optimizations enable high-yield synthesis with minimal purification requirements, combining ease of manufacture with high manufacturing precision.
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
This approach achieves high synthesis over hydrolysis ratios and efficient coupling in aqueous media, even with sterically demanding functional groups, resulting in high-yield production of peptides like Liraglutide and Semaglutide with improved purity and reduced reliance on toxic reagents.
Implementation Method 1
A method involving enzymatic coupling of specific peptide fragments using a subtilisin BPN' variant or homologue as a ligase
Implementation Method 2
overcoming the limitations of hydrolysis and racemization by optimizing the active site mutations and fragment sequences, allowing high yield and purity
Data Source
AI summary
The invention relates to a method for synthesising a peptide comprising the sequence His-X-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Y-Glu-Phe-lle-Ala-Trp-Leu-Val-Z-Gly-Arg-Gly, comprising enzymatically coupling (a) a peptide C-terminal ester or thioester comprising a first peptide fragment comprising the sequence His-X- Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-(thio)ester; and (b) a peptide nudeophile having an N-terminally unprotected amine comprising a second peptide fragment comprising the sequence H-Ser-Tyr-Leu-Glu-Gly-Gln-Ala -Ala-Y-Glu-Phe-lle-Ala-Trp-Leu-Val-Z- Gly-Arg-Gly wherein - X is Ala or an α-amino-isobutyric acid (Aib) residue - Y is Lys, which Lys has a free side-chain ε-amino group or of which Lys the side-chain ε-amino group is protected with a protective group or of which Lys the side-chain ε-amino group is functionalised with an amino acid or another functional group - Z is Arg or Lys.