Recombinant proteins and expression systems

Recombinant proteins are manipulated versions of native proteins produced using recombinant DNA to generate large amounts of a specific protein. The recombinant DNA is cloned into a vector introduced in a specific expression system (eg, mammalian, bacteria, yeast, or insect cells) to support the expression of the gene of interest and the production of the recombinant protein. Specifically, a bioactive protein is a protein that elicits an effect or response in a biological system.

Pure, high-quality proteins with high batch-to-batch consistency are critical for reliable results in biological research. When purchasing a commercially produced recombinant protein, it is also important to consider the expression system used for production. Each protein expression system has different features and applications and is chosen based on the protein type, function, and required yield.

Abcam offers two ranges of bioactive proteins, depending on your needs:

We have an extensive range of high-quality proteins made in various expression systems, so you can find a protein that fits your experimental needs.

There are many expression systems across the biological kingdoms, including cell-free methods, and systems using cell lines from bacteria, plants, fungi, insects, and mammals (including humans).

Proteins produced in prokaryotes do not undergo post-translational modifications (PTMs) such as glycosylation, phosphorylation, or proteolytic processing. PTMs are involved in folding processes, stability, and biological activity. Although prokaryotic expression systems are suitable for many applications, human-origin proteins produced in bacterial systems may not be folded or modified correctly, so they won’t necessarily function in the same way as their native-identical counterparts nor be as stable.

Prokaryotic-produced proteins are less expensive to manufacture but could be more costly over the lifecycle of a project. The expression system used when proteins are manufactured can impact activity, usefulness in downstream applications, and protein stability. Understanding these factors are crucial to ensure you don’t experience extra expense when purchasing proteins. It may be more cost-effective to start with a more costly protein that will save you money in the long run due to its increased stability (and therefore shelf life) or higher levels of activity.  

Below we introduce the most popular protein expression systems for recombinant protein production, with a brief summary of the key features of each method.