Predicting Polypeptide Side-Chain Degradation via Hybrid MD and Quantum Mechanics

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Solution Overview

Problem

Conventional molecular-dynamic simulations are inadequate for modeling chemical degradation in biologics, such as isomerization and deamidation, which can lead to reduced potency and potential health issues like Alzheimer's disease, as they fail to accurately predict sub-atomic interactions and covalent-bond changes.

Innovation Solution

A computer-implemented method using molecular-dynamics simulations to predict the likelihood of chemical degradation in polypeptide molecules by identifying spatial characteristics like inter-atom distances, angles, and dihedral angles, and estimating reaction probabilities through the analysis of polymer conformations, including solvent accessibility and acidity constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional molecular-dynamic simulations are used, then simulation speed and ease of operation are improved, but accuracy in predicting chemical degradation (sub-atomic interactions and covalent-bond changes) deteriorates

Engineering Contradiction:
Improvesimulation executionVSAvoiddegradation prediction accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The simulation process is divided into two distinct stages: (1) conventional molecular-dynamics simulation to generate polymer conformations, and (2) quantum-mechanics-based analysis to evaluate chemical degradation likelihood. This segmentation allows each method to be used in its optimal capacity - classical MD for sampling and quantum mechanics for accurate reaction prediction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A hybrid computational framework acts as an intermediary between conventional molecular-dynamics simulations and quantum-mechanics-based degradation analysis. The MD simulation generates conformational ensembles that are then fed into the quantum-mechanics engine (such as DFT-based transition state search) to predict degradation pathways, combining the strengths of both approaches.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If quantum-mechanics-based simulations are used to accurately model sub-atomic interactions and covalent-bond changes, then degradation prediction accuracy is improved, but computational complexity and processing time increase

Engineering Contradiction:
Improvedegradation prediction accuracyVSAvoidsimulation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of applying quantum-mechanics-based simulations to the entire polymer system, the method applies them selectively only to specific side-chain regions where degradation is likely to occur. This partial application reduces computational complexity while maintaining accuracy for the critical degradation-prone areas.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system is segmented into regions requiring different levels of computational treatment: the polymer backbone and bulk environment are treated with conventional molecular-dynamics, while only the specific side-chain regions prone to degradation are analyzed using quantum-mechanics methods. This selective segmentation manages computational complexity effectively.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If comprehensive spatial characteristics analysis is performed for all polymer conformations, then degradation detection precision is improved, but processing time and computational resources increase

Engineering Contradiction:
Improvedegradation detection precisionVSAvoidsimulation processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

Spatial characteristics such as inter-atom distances, angles, and dihedral angles are pre-calculated and stored for each polymer conformation generated by molecular-dynamics simulation. These pre-computed geometric parameters are then used directly in the degradation likelihood assessment without requiring repeated complex calculations, saving significant processing time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The analysis focuses computational resources on locally identifying critical spatial features that are most relevant to degradation - such as specific inter-atom distances in side-chains or particular dihedral angle configurations - rather than uniformly analyzing all possible spatial characteristics of the entire polymer, improving efficiency while maintaining detection precision.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20220208309A1Prediction of side-chain degradation in polymers through physics based simulations
Publication Date: 2022.06.30 GENENTECH INC
  • US20220208309A1 patent drawing
  • US20220208309A1 patent drawing
  • US20220208309A1 patent drawing

AI summary

The present disclosure relates to polypeptide therapeutics, and in particular to techniques for predicting side-chain degradation in polymers through physics based simulations. Particularly, aspects of the present disclosure are directed to generating a representation of a polymer having one or more side chains, performing a molecular-dynamics simulation using the representation to obtain a set of polymer conformations, determining, for each polymer conformation, one or more spatial characteristics of the polymer while in the polymer conformation, identifying, based on the one or more spatial characteristics, an incomplete subset of the set of polymer conformations estimated to undergo one or more reactions of a particular type, and estimating, based on a size of the incomplete subset, a probability of a reaction in which the polymer is a reactant and a particular other molecule is a product.