G-CSF Purification Process Using Chaotropic Solubilization

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Solution Overview

Problem

Current methods for producing granulocyte colony stimulating factor (G-CSF) from E. coli are complex, costly, and inefficient, leading to high unit costs and yield losses due to the formation of insoluble inclusion bodies and the need for multiple chromatography steps, which complicates the recovery and purification process.

Innovation Solution

A novel process involving lysing E. coli cells, isolating inclusion bodies with an ionic surfactant, solubilizing with a high-concentration chaotropic agent and denaturing agent, oxidizing with a cystine/cysteine ratio, refolding in temperature-controlled conditions, concentrating using Tangential Flow Filtration, desalting, and subjecting to cation exchange and strong-basic anion exchange chromatography to recover purified G-CSF in a stable form.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If G-CSF is produced in E. coli prokaryotic cells, then production cost is reduced and expression level is increased, but the protein forms inactive inclusion bodies that require complex solubilization and refolding steps

Engineering Contradiction:
Improveexpression levelVSAvoidpurification process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent performs preliminary solubilization of inclusion bodies using a high-concentration chaotropic agent (6M guanidinium hydrochloride) before purification steps. This preliminary action converts the insoluble inclusion bodies into soluble denatured protein, enabling subsequent straightforward purification without complex refolding steps during the purification process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical-chemical parameters of the inclusion bodies by using extreme conditions: high concentration chaotropic agent (6M guanidinium HCl) for solubilization, followed by controlled refolding conditions (pH 8.0, temperature control, oxidizing agents). These parameter changes transform the insoluble inclusion bodies into soluble, then folded, active protein.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple chromatography steps are used for purification, then purity is increased, but production time and cost increase

Engineering Contradiction:
Improvepurification purityVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent combines multiple purification functions into fewer steps. The strong-basic anion exchange chromatography step simultaneously achieves purification and endotoxin removal, which would normally require separate steps. The refolding step also serves as a concentration step, combining multiple functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The strong-basic anion exchange resin serves multiple functions: it purifies G-CSF from other proteins and simultaneously removes endotoxins from the preparation. This multi-functionality reduces the number of separate steps needed while maintaining high purity and safety standards.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If inclusion bodies are formed, then protein stability during expression is improved, but endotoxin contamination increases and requires additional removal steps

Engineering Contradiction:
Improveprotein stabilityVSAvoidendotoxin contamination
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of inclusion bodies (which trap endotoxins) into a benefit. The strong-basic anion exchange chromatography step specifically targets and removes endotoxins from the preparation, transforming the contamination problem into a straightforward removal step that also serves as the final purification step.

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

4Productivity

If high-concentration chaotropic agent is used for solubilization, then solubilization efficiency is increased, but subsequent desalting and purification complexity increases

Engineering Contradiction:
Improvesolubilization efficiencyVSAvoiddesalting process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the desalting function with the purification function by using gel filtration chromatography after the strong-basic anion exchange step. This combines buffer exchange, salt removal, and final purification into a single step, eliminating the need for separate desalting operations.

Inventive Principle:
Principle #5Merging (Combining)

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

This process simplifies and cost-effectively produces high-yield, stable G-CSF with fewer steps, reducing production time and costs while ensuring the removal of endotoxins, resulting in a commercially viable and industrially applicable method for G-CSF purification.

Implementation Method 1

isolating inclusion bodies (IBs) comprising G-CSF in the presence of ionic surfactant agent

Methodology Applied
Scientific EffectSurfactant: Surfactant

Implementation Method 2

solubilising the G-CSF present in the insoluble material, using a high concentrated chaotropic agent

Methodology Applied
Scientific EffectChaotropic agent:

Implementation Method 3

oxidizing the G-CSF in the presence of cystine/cysteine wherein the molar ratio is 1:10

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 4

oxidizing the G-CSF in the presence of cystine/cysteine wherein the molar ratio is 1:10

Methodology Applied
Scientific EffectRedox Reactions: Redox Reactions

Implementation Method 5

refolding the G-CSF in temperature controlled conditions by a one step method

Methodology Applied
Scientific EffectTemperature control:

Implementation Method 6

concentrating the refolded G-CSF solution by using Tangential Flow Filtration (TFF) system

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 7

subjecting the G-CSF solution to cation exchange chromatography

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 8

removing endotoxin by using strong-basic anion exchange chromatography

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Data Source

PatentEP2341061B1A novel process for preparing G-CSF (granulocyte colony stimulating factor)
Publication Date: 2013.07.31 ARVEN ILAC SANAYI VE TICARET
  • EP2341061B1 patent drawingFigure 1
  • EP2341061B1 patent drawingFigure 2~3
  • EP2341061B1 patent drawingFigure 4

AI summary

The present invention is related to a novel process of isolating and purifying granulocyte colony stimulating factor (G-CSF) from a G-CSF-producing microorganism, more specifically G-CSF is recombinant methionyl human G-CSF (rmetHuG-CSF).