Cell-Free Protein Synthesis For Rapid Drug Discovery

Overview

Drug targets are biological molecules, usually proteins, that medicines interact with to produce effects that treat illnesses, stop the progression of diseases, or relieve symptoms of incurable disabilities.

However, when testing new medicines, using real membrane proteins will drastically extend the period of R&D. Therefore, scientists have begun to discover alternate methods of producing different classes of proteins in order to use for analysis and reconfiguration of drugs. Cell-free protein synthesis (CFPS) is used to implement this production of proteins without living cells. Several cell-free systems exist, and they originate from prokaryotes, fungi, plants, insects, etc.

Cell-free lysates are especially useful for this type of development, since they are in liquid form and contain enzymes, ribosomes, and tRNAs without any cell membrane.

Strengths

1. Time Reduction
   1. Because there’s no need to keep host cells alive, time for producing proteins is cut down from either days to weeks to possibly hours.
2. Unfavorable Proteins
   1. Toxic proteins that may normally kill host cells can be produced.
   2. Insoluble proteins or those that are more challenging to express in living organisms can be synthesized.
3. Customization
   1. Manipulate pH
   2. Incorporate different amino acids

Weaknesses

1. Lower Protein Yield
   1. Generally, synthesizing these proteins without cells will take a shorter time but also produce less material. This means that the process may have to be repeated more frequently.
2. Loss of Certain Structures/Function
   1. Because these proteins do not come directly from a cell, certain structures, like the cell membrane, may not be analyzed.
3. High Cost
   1. Considering the cost of R&D, some researchers may still opt for in vivo protein synthesis due to the fact that it is well known and common, therefore using less resources.

Comparison (Cell-Free vs In Vivo)

Credit: Gregorio, Levine, Oza

https://pmc.ncbi.nlm.nih.gov/articles/PMC6481089

Sources

Cell-Free Protein Synthesis: A Promising Option for Future Drug Development

Cell-free protein synthesis platforms for accelerating drug discovery

A simplified and highly efficient cell-free protein synthesis system for prokaryotes

A User’s Guide to Cell-Free Protein Synthesis

Cell Free Protein Synthesis: Pros and Cons of Prokaryotic and Eukaryotic Systems