Organic Anion Stabilization of Peptides Against Deamidation
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Solution Overview
Problem
Current methods lack effective and pharmaceutically acceptable ways to prevent non-enzymatic deamidation of asparaginyl residues in peptides and proteins, which leads to significant degradation and loss of activity in biopharmaceuticals, affecting their stability and efficacy.
Innovation Solution
The use of organic anions such as saccharin, benzenesulfonic acid, and gentisic acid with a pKa within the range of 0.5 to 3.5, in excess to the total number of asparaginyl or glutaminyl residues, to stabilize peptides and proteins against deamidation, thereby forming a molar excess to any destabilizing anions present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If peptides or proteins are formulated in aqueous solution for ready-to-use administration, then ease of operation and patient convenience are improved, but non-enzymatic deamidation of asparaginyl residues occurs leading to degradation and loss of activity
Solution Approach 1:
The patent introduces organic anions (saccharin, benzenesulfonic acid, gentisic acid, and related compounds) as intermediary substances that mediate between the aqueous solution environment and the peptide/protein. These anions specifically protect asparaginyl residues from deamidation by forming protective complexes or altering the local chemical environment, thereby enabling stable ready-to-use aqueous formulations without requiring lyophilization.
Solution Approach 2:
The patent changes the chemical parameters of the aqueous formulation by adding specific organic anions with particular pKa values (ranging from 0.5 to 3.5). This parameter change creates a protective chemical environment that prevents deamidation while maintaining the peptide/protein in its active conformational state, thus achieving both stability and ease of use.
2Reliability
If lyophilized form is used to prevent deamidation, then stability is improved, but reconstitution is required before administration increasing complexity and time
Solution Approach 1:
The organic anions serve as protective intermediaries that enable the peptide/protein to remain stable in aqueous solution without requiring the protective dry state of lyophilization. This eliminates the need for reconstitution steps while maintaining stability through the chemical protective effect of the anions.
3Temperature
If common buffer components like phosphate are used, then pH control is improved, but deamidation reactions are accelerated
Solution Approach 1:
The patent changes the buffer system parameters by replacing common phosphate buffers with organic anion-based buffer systems having specific pKa values (0.5-3.5). This parameter change allows pH control to be maintained while simultaneously preventing deamidation, as the organic anions provide both buffering capacity and protective effects against deamidation.
Solution Approach 2:
The organic anions act as intermediary buffer components that control pH without accelerating deamidation. Unlike phosphate ions which directly promote deamidation, these organic anions mediate pH control through alternative mechanisms that do not involve promoting the succinimide formation pathway.
4Reliability
If extreme pH values are used to limit deamidation, then stability is improved, but solubility and formulation flexibility are reduced
Solution Approach 1:
The patent changes the formulation parameters by introducing organic anions with specific pKa ranges, which allows the formulation to maintain physiological or near-physiological pH values while achieving deamidation protection. This parameter change restores formulation flexibility and solubility that would otherwise require extreme pH values.
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 significantly decreases non-enzymatic degradation rates, allowing for the formulation of stable aqueous solutions with a shelf-life of at least two years, enabling ready-to-use formulations and reducing the risk of adverse reactions associated with deamidation.
Implementation Method 1
The first step in base-catalyzed deamidation of a peptide or protein at an asparaginyl or glutaminyl residue is usually nucleophilic attack of the adjacent main-chain nitrogen on the carbonyl, giving off an ammonia molecule, to form a short-lived intermediate which is a succinimide
Implementation Method 2
water can attack the succinimide after the nucleophilic attack, so that attack by water is not the initial step
Data Source
AI summary
Stabilization of water-containing solutions or lyophilizates of proteins and peptides against non-enzymatic deamidation degradation reactions at asparaginyl or glutaminyl residues is achieved using organic anions, such as saccharin, benzenesulfonic acid, gentisic acide or N-acetyltryptophan which have a pKa within the range of 0.5 to 3.5.