Sortase-Mediated Protein Modification on Living Cells
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Solution Overview
Problem
Current methods for modifying proteins expressed by living animal cells require genetic engineering or the use of crosslinking reagents, which can be cumbersome and inefficient.
Innovation Solution
The use of sortase-mediated reactions to conjugate agents to endogenous, non-genetically engineered proteins on living animal cells, without the need for genetic modification or crosslinking reagents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If genetic engineering is used to modify proteins on living animal cells, then site-specific modification can be achieved, but the process becomes cumbersome and requires complex genetic manipulation
Solution Approach 1:
The patent introduces a sortase enzyme as an intermediary that mediates the conjugation between a protein on the cell surface and a modification substrate. The sortase recognizes a specific peptide sequence (LPXTG) and catalyzes the formation of a covalent bond, enabling site-specific modification without genetic engineering. This intermediary enzyme bridges the gap between the cell surface protein and the modification agent, resolving the contradiction by providing precision through enzymatic specificity while avoiding complex genetic manipulation.
2Ease of manufacture
If crosslinking reagents are used to conjugate agents to cell surface proteins, then modification can be achieved, but the method lacks specificity and requires additional reagents
Solution Approach 1:
The sortase enzyme serves as a specific intermediary that replaces non-specific crosslinking reagents. It recognizes a defined peptide sequence and catalyzes conjugation at that specific site, providing both ease of use (simple incubation conditions) and high specificity (sequence-dependent recognition). This eliminates the need for additional crosslinking reagents while maintaining or improving conjugation precision.
Solution Approach 2:
The method changes the key parameter of conjugation from non-specific chemical reactivity to specific enzymatic recognition. By using sortase that recognizes the LPXTG sequence, the system transforms the conjugation process from a broad, non-specific chemical reaction to a targeted, sequence-specific biochemical reaction, thereby achieving both ease of operation and high precision.
3Manufacturing precision
If sortase recognition motifs are engineered into proteins, then sortase-mediated modification can be achieved, but this requires genetic modification of the cell
Solution Approach 1:
The sortase recognition peptide sequence is pre-installed on the cell surface protein during its natural synthesis or through a separate tagging step, before the sortase-mediated conjugation occurs. This preliminary placement of the recognition motif allows the endogenous sortase to subsequently act on the protein with high specificity, achieving precise modification without requiring genetic engineering of the entire cell or protein expression system.
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 allows for efficient and specific modification of proteins on living cells, enabling the attachment of various moieties such as antibodies, peptides, and therapeutic agents, without altering the cellular genetics.
Implementation Method 1
The transpeptidation reaction catalyzed by sortases has emerged as a versatile method for site-specific modification of proteins
Implementation Method 2
Staphylococcus aureus sortase A recognizes a set of diverse substrates via a sortase recognition motif (e.g., LPXTG) and cleaves the peptide bond between threonine and glycine
Data Source
AI summary
Non-genetically engineered mammalian cells modified by sortase-mediated conjugation of an agent thereto are provided. Methods of conjugating agents to non-genetically engineered mammalian cells using sortase are provided. Methods of using the cells, e.g., for diagnostic and/or therapeutic purposes, are provided.