Alpha Lifetech Inc. focuses on recombinant proteins expression in different Biosystems for many years, including prokaryotic and eukaryotic organisms, as well as the development of novel high-potency recombinant proteins.
Conventional methods, such as Mammal Expression System, Insect Expression System, Bacteria Expression System and Yeast Expression System, for the preparation of integral membrane proteins have intrinsic limits in membrane proteins' expression, because the production of membrane proteins is a challenging task as their hydrophobic nature and their specific requirements in cellular expression systems frequently prevent an efficient synthesis. So far, a considerable number of membrane proteins from diverse families like prokaryotic small multidrug transporters (SMTs) or eukaryotic G-protein coupled receptors (GPCRs) have been produced in cell-free systems in high amounts and in functionally active forms.
Cell-free Protein Expression System - Recombinant Proteins/Antibodies
Cell-free expression systems offer unique advantages when compared to cell-based protein expression due to problems associated with cellular toxicity, low expression, or aggregation. Cell-free protein synthesis systems are not as sensitive to toxic proteins such as kinases and membrane proteins, and modified tRNAs can be used for labeling, and unnatural amino acids can be incorporated at specific sites.
Figure 1 Cell-free Expression Systems of Recombinant Proteins
Alpha Lifetech Inc. creates several premade systems based on cell lysates (see as Fig.1) to express recombinant proteins including membrane proteins (MPs) and virus-like particles for our clients by using different cell-free protein expression systems in a short turnaround time. According to different applications, Alpha Lifetech Inc. develops several cell-free systems to express recombinant proteins, including Bacterial Cell-free Expression, Wheat Germ Cell-free Expression, Insect Cell-free System and Mammal Cell-free Expression.
Bacterial Cell-free Expression
AlphaBacTM, bacterial in vitro expression systems use an efficient coupled transcription and translation reaction to produce high yields of full-length, functional protein from E. coli cell lysates.
Wheat Germ Cell-free Expression (WGC)
WGC Expression System had been used to express special proteins, typically membranes proteins, which require more modifications, such as glycosylation, phosphorylation, efficient disulfide bridge formation and native refolding. Wheat germ extracts have a very low endogenous RNAse activity allowing their use in translation systems with purified mRNA as a template. Alpha Lifetech Inc. creates a state-of-art platform based on Wheat Germ Cell-free Expression and makes it possible that yields of recombinant proteins reach to gram magnitude.
Insect Cell-free Expression (ICE)
Insect Cell-free Expression System (ICE) is the most widely used eukaryotic system. Concerning glycosylation, ICE has the advantage over the Rabbit Reticulocyte Cell-free Expression System (RRC) as using ICE, the core glycosylation does not require the addition of microsomal membranes, which have been shown to provide the compartmentalization and enzymes needed for proper post-translational modifications in RRC.
Mammal Cell-free Expression (MCE)
AlphaMamTM platform contains Rabbit Reticulocyte System, HeLa Cell-Free System and CHO Cell-Free System. Mammalian-based cell-free protein systems derived from Rabbit Reticulocyte, HeLa and CHO offer a biochemical environment closely related to living human cells and also offer a better acceptance of human genes as templates for the synthesis and correct folding of complex and multimeric human proteins.