Alpha-1-Antitrypsin Purification via Selective ApoA-I Precipitation
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Solution Overview
Problem
Current methods for purifying alpha-1-antitrypsin (AAT) and Apolipoprotein A-I (ApoA-I) from human plasma are inefficient and costly, often resulting in the loss or inactivation of AAT during the separation process, and both proteins are typically discarded as contaminants in each other's purification processes, limiting the yield and purity of pharmaceutical-grade products.
Innovation Solution
Developing methods to separate AAT from ApoA-I at the initial stage of purification, using techniques such as adjusting pH and lower aliphatic alcohol concentrations to precipitate ApoA-I while keeping AAT in solution, followed by further purification using ion exchange and hydrophobic interaction chromatography, minimizing deamidation and denaturation, and employing ApoA-I binding agents like fumed silica to achieve pharmaceutical-grade purity for both proteins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional purification methods are used to isolate AAT from human plasma, then AAT can be obtained, but ApoA-I is lost as a contaminant and the process is inefficient and costly
Solution Approach 1:
The invention segments the purification process into distinct stages: initial separation of ApoA-I containing fractions from plasma, followed by separate purification pathways for AAT and ApoA-I. This allows both proteins to be recovered from the same starting material rather than losing one as contaminant during the other's purification
Solution Approach 2:
The invention utilizes parameter changes in pH and alcohol concentration to selectively precipitate ApoA-I while keeping AAT in solution during the initial separation stage. This selective precipitation based on differential solubility parameters enables efficient separation without loss of either protein
2Ease of manufacture
If traditional purification methods are used, then AAT purification can proceed, but AAT is inactivated during the separation process
Solution Approach 1:
The invention performs preliminary separation of ApoA-I from the plasma fraction before proceeding with AAT purification. By removing ApoA-I first through selective precipitation, subsequent AAT purification steps can proceed without conditions that would cause AAT inactivation or loss
Solution Approach 2:
The invention uses selective precipitation with alcohol and pH adjustment as an intermediary step between plasma and final AAT purification. This intermediary separation protects AAT from inactivation by removing interfering substances before AAT-specific purification steps
3Productivity
If both proteins are purified from the same plasma fraction, then yield and purity can be maximized, but complex separation techniques are required
Solution Approach 1:
The invention employs relatively simple parameter changes (pH adjustment and alcohol addition) to achieve selective precipitation of ApoA-I. This avoids the need for complex chromatographic or ultracentrifugation-based separation techniques while still achieving high yield and purity for both proteins
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 methods enable large-scale purification of AAT and ApoA-I with high yield and purity (>95%) while preventing deamidation and denaturation, reducing the risk of immunogenic reactions and achieving cost-effective production of pharmaceutical-grade proteins.
Implementation Method 1
employing ApoA-I binding agents like fumed silica to achieve pharmaceutical-grade purity for both proteins
Implementation Method 2
adjusting pH and lower aliphatic alcohol concentrations to precipitate ApoA-I while keeping AAT in solution
Implementation Method 3
followed by further purification using ion exchange and hydrophobic interaction chromatography
Implementation Method 4
followed by further purification using ion exchange and hydrophobic interaction chromatography
Data Source
AI summary
This invention relates to protein separation and purification methods for both alpha-1-antitrypsin (AAT, also known as alpha-1 proteinase inhibitor, API, and A.sub.1-PI) and Apolipoprotein A-I (ApoA-1) from, for example, a fraction of human blood plasma. In certain embodiments, the invention provides methods for separating AAT from ApoA-1 at the initial stage of purification, so that the same starting material can be used as a source for both proteins. The methods further pertain to providing compositions of AAT and of ApoA-1 suitable for pharmaceutical use and are suitable for large-scale purification.