Why are alternatives to Protein A capture being actively pursued?

Question

BlackTom AI · Accepted Answer

Protein A’s high cost, modest dynamic binding capacity compared with some ion-exchange (IEX) resins, and sensitivity to aggressive cleaning agents are the main drivers for seeking alternative capture strategies.

1) Relevant knowledge points and concepts
- Protein A affinity chromatography selectively binds IgG Fc regions and is widely used for monoclonal antibody (mAb) capture because of high selectivity and purity.
- Dynamic binding capacity (DBC) measures how much product a resin can bind under flow; higher DBC increases throughput and reduces resin volume required.
- Resin lifetime and cleaning-in-place (CIP) tolerance determine overall process economics; resistance to harsh sanitants (e.g., NaOH) extends usable cycles.
- Cost of affinity ligands and resin manufacturing contributes substantially to downstream costs at commercial scale.

2) Step-by-step reasoning
- Protein A resins deliver excellent selectivity and product quality but are expensive to produce and purchase (high ligand cost and complex immobilization chemistry).
- Compared to modern IEX resins, Protein A often exhibits lower DBC for some antibodies, meaning larger column volumes or more frequent replacement—raising cost.
- Protein A ligands are often less tolerant to repeated exposure to strong alkaline CIP (e.g., 0.5–1.0 M NaOH) and other harsh cleaning agents, which shortens resin lifetime and raises recurring costs.
- These combined economic and operational limitations motivate exploration of alternatives (e.g., mixed-mode, improved IEX, non-protein ligands, or engineered affinity ligands).

3) Calculations/intermediate steps
- No numerical calculations required; logical steps above show how cost, capacity, and CIP tolerance impact resin use and economics.

4) Why the correct answer is correct
- The chosen option explicitly lists the three key limitations—expense, lower capacity vs IEX, and limited cleaning tolerance—that are commonly cited in literature and industry discussions as reasons to pursue alternatives.

5) Why other options are incorrect
- Option A (poor platform selectivity across IgG subclasses) is incorrect: Protein A generally binds IgG1, IgG2, IgG4 well (though subclass differences exist, it is broadly platformable).
- Option C (requires gradient elution) is incorrect: Protein A typically uses mild, low-pH step elution, not gradient elution, and is compatible with robust manufacturing.
- Option D (cannot be scaled to manufacturing column diameters) is incorrect: Protein A has been scaled successfully to large commercial columns; scaling is not the primary limitation.

6) Conclusion
The correct answer is: "Protein A is expensive, has relatively low capacity vs IEX resins, and has limited tolerance to harsh cleaning agents," which matches the provided answer.

Why are alternatives to Protein A capture being actively pursued?单项选择题

类似问题

Protein A column regeneration is typically carried out with:

Which statement is NOT true about Protein A as an industry-standard capture resin?

In Fig. 5.2, the elution peak is narrow and tall. What does this most strongly indicate?

Protein A column regeneration is typically carried out with:

Nonspecific binding is rarely minimized in practice primarily because:

§5.3 states the simplest general approach to reduce aggregation/precipitation during Protein A elution is often:

Gottschalk (and Kelley) note that the Protein A capture step is generally robust, but some [of its] variables may still be influenced by product or feed-stream variations. Which option best lists those variables?

Which one would be the best choice to use for an affinity chromatography to purify a DNA polymerase?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单