Protein Production in Inclusion Body

Alpha Lifetech Inc. provides high-quality recombinant proteins and services for our clients. As a professional bio-manufacturer, we provide case-by-case recombinant expression service for each project.


Non-Soluble Protein Producing in Inclusion Body


Many protein species produced in recombinant bacteria aggregate as insoluble protein clusters named inclusion bodies (IBs). Overexpression of cloned or synthetic genes in Escherichia coli often results in the formation of insoluble protein IBs. The expression of toxic proteins, such as membrane proteins (MPs), in soluble forms in vitro is a very challenging task, since high-level expression of recombinant proteins in E. coli often results in the formation of insoluble and inactive aggregates known as IBs.  However, the formation of IBs offers several advantages for the production of recombinant proteins: the recombinant protein deposited in IBs amounts to about 50% or more of the total cellular protein; IBs can be isolated from the cellular proteins by centrifugation, since they have a relatively high density. Furthermore, IBs have been found that (i) protein deposition in recombinant cells is fully reversible and (ii) a relevant fraction of IB proteins is actually functional.


Fig. 1 Electron micrograph of inclusion bodies containing recombinant adenylate kinase expressed in E. coli.


Now, Alpha Lifetech Inc. has developed the platform to produce and purify recombinant proteins by isolating inclusion bodies from cell lysates. We carefully choose the condition to renature or refold the recombinant protein by using High Through Screening (HTS), since we know that both folding, and association of proteins depend strongly on temperature and pH. We have successfully expressed membrane proteins and viral capsid proteins in over 100 cases based on our renaturation and refolding technologies.