Modified Serpin RCL for TMPRSS2 Inhibition
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Solution Overview
Problem
Current serine protease inhibitors lack specificity and effectiveness in targeting TMPRSS2, a serine protease implicated in viral infections and prostate cancer, with existing small molecule inhibitors showing limitations in selectivity and efficacy.
Innovation Solution
Development of a serine protease inhibitor (Serpin) with a modified Reactive Centre Loop (RCL) containing specific amino acid substitutions at positions P4 to P1′, such as glutamine at P3, arginine at P1, phenylalanine or alanine at P2, and hydrophobic residues at P4 and P1′, to selectively inhibit TMPRSS2, utilizing SerpinB3 or alpha-1-antitrypsin as a scaffold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a serine protease inhibitor is designed to target TMPRSS2, then specificity for TMPRSS2 is improved, but effectiveness against other proteases may worsen
Solution Approach 1:
The invention modifies the Reactive Centre Loop (RCL) of the serpin at specific positions (P4 to P1') with particular amino acid substitutions (glutamine at P3, arginine at P1, phenylalanine or alanine at P2, and hydrophobic residues at P4 and P1') to create local structural features that confer high specificity for TMPRSS2 while maintaining effective inhibition of the target protease
2Reliability
If small molecule inhibitors of TMPRSS2 are developed, then inhibition of TMPRSS2 activity is achieved, but selectivity and efficacy are limited
Solution Approach 1:
The invention transitions from small molecule inhibitors to protein-based serpin inhibitors with modified RCL sequences. By changing the amino acid sequence parameters of the serpin at critical positions in the RCL, the inhibitor achieves both high efficacy in inhibiting TMPRSS2 and high selectivity over other proteases, overcoming the limitations of small molecule approaches
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
The modified Serpin achieves 92% inhibition of TMPRSS2 with low off-target binding, effectively reducing TMPRSS2 activity and inhibiting viral entry and replication, including SARS-CoV-2, while being non-cytotoxic and showing improved selectivity over other proteases.
Implementation Method 1
The modified Serpin achieves 92% inhibition of TMPRSS2 with low off-target binding
Implementation Method 2
cleavage of the P1-P1′ scissile bond of the RCL causes the serpin to undergo a conformational change, whereby the RCL inserts itself within the strands of β-sheet A
Implementation Method 3
The serine protease catalyses the cleavage of the RCL via nucleophilic attack, forming an acyl-enzyme intermediate
Implementation Method 4
The serine protease catalyses the cleavage of the RCL via nucleophilic attack, forming an acyl-enzyme intermediate
Implementation Method 5
This motion distorts the active site of the serine protease and prevents the hydrolysis of the acyl-enzyme intermediate therefore trapping the protein in this covalently bound state
Data Source
AI summary
The invention relates to a serine protease inhibitor (Serpin) comprising a modified Reactive Centre Loop (RCL), wherein the modified RCL comprises a transmembrane serine protease 2 (TMPRSS2) inhibitory sequence having one or more amino acid substitutions at positions P4 to P1′. The invention also relates to a method of treating and/or preventing a condition in a subject in need thereof, where the TMPRSS2 activity is implicated in said condition, the method comprising administering the Serpin of the present invention.