NGF R100W Recombinant Protein Secretion for Nerve Repair

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Solution Overview

Problem

Current methods for obtaining the NGF R100W mutant protein are inefficient, limiting its application in treating nerve diseases, as the full-length NGF R100W mutant protein affects normal secretion and cleavage, preventing its neurotrophic function.

Innovation Solution

A recombinant protein is developed with a modified nucleic acid molecule encoding an NGF protein variant linked to a heterologous signal peptide, which reduces binding to p75NTR by at least 50% and increases expression and secretion by at least 50%, using a delivery vector like liposomes or lipid nanoparticles to enhance delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If full-length NGF R100W mutant protein is used, then neurotrophic function is achieved, but secretion and cleavage are affected

Engineering Contradiction:
Improveneurotrophic functionVSAvoidsecretion and cleavage
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The NGF R100W mutant protein is segmented into two functional parts: a signal peptide sequence (from immunoglobulin kappa) and a mature NGF R100W mutant sequence. This segmentation allows the signal peptide to mediate proper secretion and cleavage while the mature portion retains neurotrophic function, resolving the contradiction between functional activity and manufacturability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The endogenous signal peptide is extracted and replaced with a heterologous signal peptide sequence from immunoglobulin kappa. This extracted and replaced signal peptide enables proper secretion and cleavage of the NGF R100W mutant without compromising its neurotrophic function, solving the secretion problem while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If wild type NGF is used to treat AD patients, then cognitive ability is improved, but pain side effects occur

Engineering Contradiction:
Improvecognitive ability improvementVSAvoidpain side effects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A specific point mutation (R100W) is introduced at position 100 of the NGF protein sequence. This local quality change at a specific site selectively reduces binding affinity to p75NTR (the pain-inducing receptor) while preserving binding to TrkA (the neurotrophic receptor), thereby maintaining cognitive improvement benefits while reducing pain side effects.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The amino acid sequence parameter is changed by substituting arginine (R) with tryptophan (W) at position 100. This parameter change alters the protein's interaction properties with receptors, specifically reducing p75NTR binding affinity by at least 50% while maintaining TrkA binding, thus changing the therapeutic profile from painful to painless.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If high-dose NGF is administered, then therapeutic effect is enhanced, but adverse reactions increase

Engineering Contradiction:
Improvetherapeutic effectVSAvoidadverse reactions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The fundamental parameter change of R100W mutation alters the dose-response relationship by eliminating the pain-inducing pathway. This allows administration of higher doses to achieve enhanced therapeutic effects without proportionally increasing adverse reactions, as the pain pathway is selectively blocked at the molecular level.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The harmful pain-inducing interaction between NGF and p75NTR is converted into a benefit by the R100W mutation, which selectively abolishes this harmful pathway while preserving the beneficial neurotrophic pathway through TrkA. This converts what was previously a harmful side effect into a selective therapeutic advantage.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4375367B1Recombinant protein of nerve growth factor mutant and use thereof
Publication Date: 2026.01.21 SHANGHAI RNACURE BIOPHARMA CO LTD
  • EP4375367B1 patent drawingFigure 1A~1B
  • EP4375367B1 patent drawingFigure 1C~1D
  • EP4375367B1 patent drawingFigure 1E~1F

AI summary

Provided is a recombinant protein, which contains a nerve growth factor (NGF) protein variant and a heterologous signal peptide linked to the NGF protein variant. Further provided are a combination containing an mRNA encoding the recombinant protein and a delivery vector, and the use thereof in the treatment of toxic/hereditary/metabolic peripheral neuropathy, nerve regeneration repair, and/or central nervous system degenerative diseases.