Targeted Protease Variants for High-Temperature PLA Recycling

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Solution Overview

Problem

There is a need for proteases with improved activity and stability at high temperatures to enhance the efficiency of biodegradable plastic production and recycling processes, particularly for degrading polylactic acid (PLA) plastics.

Innovation Solution

Development of protease variants with specific amino acid substitutions, such as at positions N102, S104, N107, G132, G134, or Y167, exhibiting at least 75% to 99% identity to the parent protease sequence, which show increased polyester degrading activity and stability, especially at temperatures up to 80°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wild-type protease is used, then basic polyester degrading activity is provided, but activity and stability at high temperatures are insufficient

Engineering Contradiction:
Improvepolyester degrading activityVSAvoidstability at high temperatures
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying specific amino acid residues at positions 102, 104, 107, 132, 134, and 167 of the protease sequence. These biochemical parameter changes in the enzyme structure result in improved thermostability and polyester degrading activity, transforming the wild-type protease into optimized variants that maintain reliability at high temperatures while enhancing productivity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If protease variants with multiple amino acid substitutions are developed, then polyester degrading activity increases up to 500%, but process complexity increases

Engineering Contradiction:
Improvepolyester degrading activityVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by implementing targeted amino acid substitutions at specific positions (102, 104, 107, 132, 134, 167) rather than random modifications. This localized approach to enzyme optimization allows achieving up to 500% increase in polyester degrading activity while maintaining manageable process complexity, as only specific critical regions of the protease are modified.

Inventive Principle:
Principle #3Local quality

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 protease variants demonstrate enhanced polyester degrading activity, with activity increases of up to 500% and improved thermostability, facilitating efficient degradation of PLA plastics and recycling processes.

Implementation Method 1

Proteases are able to catalyze the hydrolysis of a variety of polymers, including polyesters

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

enzymes are able to accelerate hydrolysis of polyester containing material

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Data Source

PatentEP3555281B1Improved plastic degrading proteases
Publication Date: 2025.10.22 CARBIOS

AI summary

The present invention relates to novel proteases, more particularly to protease variants having improved activity compared to the protease of SEQ ID N° 1 and the uses thereof for degrading polyester containing material, such as plastic products. The proteases of the invention are particularly suited to degrade polylactic acid, and material containing polylactic acid.