Diazaborine Polypeptide Conjugation Under Mild Conditions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for attaching labels or cargo to biological molecules, such as peptides and nucleic acids, often require harsh conditions, limiting their use in complex biological systems, and there is a need for more selective and efficient methods that can operate under mild conditions compatible with biological stability.
Innovation Solution
A method involving the modification of lysine residues in polypeptides to form a semicarbazide group, which then reacts with ortho-acyl phenylboronic acid to form a diazaborine compound, allowing for the attachment of bioorthogonal handles and subsequent conjugation to targets like surfaces, labels, or other biomolecules under mild conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional linking methods are used to attach labels or cargo to biological molecules, then conjugation can be achieved, but harsh reaction conditions are required that limit usefulness in complex biological systems
Solution Approach 1:
The patent changes the chemical parameters of the reaction by using a novel diazaborine-forming chemistry between semicarbazide and ortho-acyl phenylboronic acid. This chemical transformation enables conjugation to proceed under mild physiological conditions (aqueous buffer, room temperature, pH 6-8) rather than harsh conditions, while maintaining high conjugation reliability through the stability and selectivity of the diazaborine ring formation
Solution Approach 2:
The patent introduces an intermediary functional group transformation: the lysine side chain is first converted to a semicarbazide group, which then serves as a mediator to react with ortho-acyl phenylboronic acid. This two-step process with the semicarbazide intermediary enables mild reaction conditions while achieving reliable conjugation, as the semicarbazide is stable under physiological conditions but highly reactive toward the boronic acid
2Adaptability or versatility
If amino acid side chains are used as attachment points for conjugating peptides to cargo compounds, then conjugation can be achieved, but existing methods require unduly harsh conditions that limit their usefulness
Solution Approach 1:
The patent fundamentally changes the reaction parameters by employing a bioorthogonal chemistry approach where the semicarbazide-modified lysine side chain reacts specifically with ortho-acyl phenylboronic acid under physiological conditions. This enables versatile conjugation of peptides to various cargo compounds (nucleic acids, proteins, surfaces) without harsh conditions, as the reaction proceeds efficiently in aqueous media at neutral pH and room temperature
3Stability of the object's composition
If selective conjugation under mild conditions is achieved, then biological molecule stability is maintained, but the conjugation method must be highly selective in complex mixtures
Solution Approach 1:
The patent uses the semicarbazide group as a selective intermediary that is introduced site-specifically onto lysine residues. This intermediary has high specificity for ortho-acyl phenylboronic acid, enabling selective conjugation even in complex biological mixtures. The bioorthogonal nature of this reaction pair ensures that only the intended conjugation occurs, maintaining high manufacturing precision while preserving biomolecule stability under mild conditions
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 enables highly selective and efficient conjugation of polypeptides to various cargo compounds or surfaces, maintaining the stability and functionality of biomolecules, and is suitable for use in both solution and solid support modifications.
Implementation Method 1
Reaction of the semicarbazide with the acyl phenylboronate produces a cyclic diazaborine compound
Data Source
AI summary
The present disclosure relates to a selective and efficient method to connect a polypeptide containing at least one lysine residue to a cargo moiety, where one step of the method involves reaction of a semicarbazide group with an ortho-acylphenyl boronic acid, forming a cyclic diazaborine ring fused to phenyl. Conditions for formation of the cyclic diazaborine are sufficiently mild for the method to be used in the presence of sensitive biomolecules such as polynucleotides. A substituent group on the phenyl can be used to link the cyclic diazaborine to a cargo moiety such as a polynucleotide, bead, or reactive group, providing a polypeptide—cargo moiety conjugate that is useful for various purposes, such as to analyze, identify, track, locate, detect, or immobilize the polypeptide. Also provided are polypeptide—cargo moiety conjugates, wherein the polypeptide and cargo moiety are connected via a linker that comprises a cyclic diazaborine.