Protease Stability in Liquid Detergents via Amino Acid Substitutions

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Solution Overview

Problem

Existing proteases in washing and cleaning agents lack sufficient catalytic activity and storage stability, leading to suboptimal cleaning performance on protease-sensitive stains.

Innovation Solution

A protease from Bacillus pumilus with specific amino acid substitutions, including 9T, 144K, 252T, and 271E at positions 9, 144, 252, and 271, and additional substitutions at positions 53, 120, 131, 149, 159, 162, 166, 172, 189, 192, 211, 215, 217, 224, and 274, which enhances storage stability and catalytic activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional proteases are used in washing and cleaning agents, then they can decompose protein-containing stains, but they lack sufficient storage stability and catalytic activity under standard washing conditions

Engineering Contradiction:
Improvestorage stabilityVSAvoidamino acid sequence complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying specific amino acid residues in the protease sequence (e.g., positions 9, 144, 252, 271, and others) to optimize both storage stability and catalytic activity. This systematic alteration of molecular parameters resolves the contradiction between maintaining simple enzyme structure and achieving enhanced functional performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention implements local quality by making targeted substitutions at specific positions within the protease molecule rather than altering the entire structure. This allows localized optimization of stability and activity while preserving the overall enzyme architecture and simplicity.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If proteases are stored in surfactant-containing liquid formulations, then they can be used in liquid washing agents, but they lose catalytic activity and stability over time

Engineering Contradiction:
Improveliquid formulation compatibilityVSAvoidstorage lifespan
Core Design Contradiction:
Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The patent modifies amino acid parameters at critical positions to enhance the protease's resistance to surfactant-induced denaturation and hydrolysis. These parameter changes enable the enzyme to maintain stability and activity throughout the storage lifespan of liquid formulations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The engineered protease incorporates preemptive stabilizing mutations that cushion against the damaging effects of surfactants and storage conditions before degradation occurs. This prior protection mechanism preserves catalytic activity during extended storage in liquid formulations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If proteases are optimized for high catalytic activity, then they can effectively remove stains, but their storage stability decreases

Engineering Contradiction:
Improveproteolytic activityVSAvoidstorage stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by making targeted amino acid substitutions at specific positions (e.g., 9T, 144K, 252T, 271E) that simultaneously enhance both catalytic activity and storage stability. This localized optimization resolves the contradiction between productivity and reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention systematically changes amino acid parameters at key positions to achieve a dual optimization of proteolytic activity and storage stability, breaking the traditional trade-off between these two critical performance parameters.

Inventive Principle:
Principle #35Parameter changes

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 protease exhibits improved storage stability and increased catalytic activity, leading to enhanced washing performance on protease-sensitive stains, even after extended storage periods.

Implementation Method 1

They act as non-specific endopeptidases and hydrolyze any acid amide bonds that are inside peptides or proteins

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS12338469B2Proteases having improved enzyme stability in washing and cleaning agents III
Publication Date: 2025.06.24 HENKEL KGAA

AI summary

Proteases may include an amino acid sequence having at least 70% sequence identity with the amino acid sequence given in SEQ ID NO: 1 over its entire length and, in each case based on the numbering according to SEQ ID NO: 1, may include (i) amino acid substitutions, such as selected from amino acid substitutions 9T, 144K, 252T and 271E, at positions corresponding to positions 9, 144, 252 and 271, and (ii) at least one additional amino acid substitution at least at one of the positions corresponding to positions 53, 120, 131, 149, 159, 162, 166, 172, 189, 192, 211, 215, 217, 224 and 274. Production and use of said proteases are described herein. Proteases of this kind demonstrate very good stability with a good cleaning performance.