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•  Wheat Germ Cell-free Protein Expression

Chemical synthesis, in vivo expression, and cell-free protein synthesis are the three main strategies for protein production. Chemical synthesis is not practical for the synthesis of long peptides, and protein expression in vivo can only produce proteins that do not affect the physiological function of the host cell. In contrast, cell-free expression systems can synthesize proteins with high accuracy and at speed approaching in vivo rates, and can express proteins that interfere with cell physiology.

Cell-free protein expression plays an important role in biochemical studies and protein high throughput production. Common cell-freer expression systems are derived from E. coli extract, wheat germ extract, and rabbit reticulocyte lysate. Wheat germ system provides the highest translation efficiency among the eukaryotic systems and has a very high success rate for the expression of high-quality soluble proteins. As an in vitro protein expression method, the wheat germ system is a preferable choice for many applications in protein research including options for protein labeling and the expression of difficult-to-express proteins such as membrane proteins and multiple protein complexes.

Wheat Germ Cell-free Protein Expression System

The wheat grain consists of the bran, endosperm, and germ. Since the germ is in a dormant stage, it is extraordinarily rich in protein factors and ribosomes that are necessary for rapidly performing protein synthesis from stored mRNAs during early germination. In addition, eukaryotic ribosomes from plants are better adapted for protein folding during synthesis than prokaryotic ribosomes from E. coli extracts.

According to research findings, the extremely low translation activity of wheat germ expression system was due to the presence of translation inhibitors in the reaction solution. In 2000, the wheat germ cell-free protein expression system (ENDEXT) technology was developed, which greatly improves synthesis by removing translation inhibitors originating in the germ.

Product Range

Features

• Capable of expressing proteins derived from a variety of species
• Easy to express the properly folded proteins
• Easy to express soluble proteins
• Limited degradation of the synthesized proteins
• No glycosylation and thus no attachment of foreign sugar moieties

Operational Process

The synthesis of the target protein takes at least 4 days when a PCR product is used as template DNA and at least 10 days when the vector is used.

Proprietary Synthesis Technology- Bilayer Method

Wheat germ extract has high protein synthesis activity, and the method of protein synthesis is important to maximize its benefit. A proprietary technology has been developed to solve the problems of conventional methods such as the batch method and the dialysis method. Bilayer method provides high yield proteins by forming two layers in the form of wheat germ extract and substrate solution so that substrates are slowly diffuse and dispersed through the contact surface.

Bilayer method can be fully automated for large-scale and efficient screening. Its flexible format permits screening different additives for the translation reaction, such as detergents or lipids for the expression of membrane proteins in a soluble form. Moreover, bilayer method has higher synthetic efficiency than the batch method, where substrates are completely consumed within a few hours and the reaction stops. Although protein production is higher in the dialysis mode, the cost is proportionally higher in the case of protein labeling because of the larger buffer volume.

*Our products can also be used to synthesize target proteins using the dialysis method.

Protein Expression Kits

In addition to natural proteins, the wheat germ cell protein-free expression system can also be used to express artificial proteins, such as preparing stable isotope-labeled peptide libraries. The wheat germ system can be compatible with high-resolution structural biology methods such as cryo-electron microscopy (cryo-EM), X-ray crystallography, solution nuclear magnetic resonance (NMR), and solid-state NMR. The unique possibilities of the system for studying cytotoxic proteins, complex membrane proteins or molecular assembly in a native-close state create opportunities for structural approaches to study complex proteins.

Easy access to proteins to support routine research needs

Expression of proteins with disulfide bonds

Protein labeling for flexible customer need

Protein labeling for protein mass spectrometry (MS)

Protein labeling for Nuclear Magnetic Resonance (NMR)

Expression of membrane proteins into proteoliposomes

Comparison of Representative Protein Expression Systems