In vitro E.coli __expression__ system, also known as cell-free protein __expression__ system or the in vitro translation system, simulates in vivo cells and reproduces the intracellular protein transcription and translation process. It needs the existence of various materials required for protein synthesis, including energy, transcription factors, and translation factors, etc.

The system is particularly suitable for the __expression__ of transmembrane proteins and toxic proteins. Its feature includes short cycle and high-throughput. CUSABIO has mastered the full set of core technology of E.coli cell-free __expression__ system, all core components are produced in house, and the reaction system contains more than 40 ingredients, which are easy to be adjusted and optimized.

Service Process

Step 1:		Step 2: Small-scale __expression__ and optimization Target protein __expression__ and purification
Plasmid construction and preparation (15-20 business days)		7-10 business days (Additional 3 business days for multi-condition purification)

Step 3: Additional services (optional) Additional services (optional) Endotoxin removal, Filter-sterilization (2 business days, free)

Step 4: Quality Control (3-5 business days)

Since the establishment of this platform in 2015, 162 proteins have been successfully produced with yield of mg/ml, which contains 99 transmembrane proteins with 1-12 transmembrane domains and toxic proteins that are difficult to express in traditional E.coli __expression__ systems. We have also produced high molecular weight proteins (130 kDa -140 kDa) that contain multiple transmembrane domains.

Project Showcase

Case 1: The following three items are proteins with 5, 6 and 7 transmembrane domains separately.

		Lane 1: Reaction Condition1 Lane 2: Reaction Condition 2 Lane 3: Reaction Condition 3 Lane 4: Reaction Condition 4 Lane 5: Reaction Condition 5 Lane 6: Reaction Condition 6

Case 2: The project was a 9 transmembrane protein.

Lane 1: Reaction Condition1 Lane 2: Reaction Condition 2 Lane 3: Reaction Condition 3 Lane 4: Reaction Condition 4 Lane 5: Reaction Condition 5

Case 3: The protein in this project had a very low yield. Through optimization of different N-terminal peptides, the yield was improved dramatically, as shown in Figure 5.

Lane 1: Tag 1 Lane 2: pET-28a(+) control Lane 3: Tag 2 Lane 4: Tag 3 Lane 5: Tag 4 Lane 6: Tag 5 Lane 7: Tag 6 Lane 8: Tag 7

Case 4: HTR1B is a membrane protein of the GPCR family. It contains 7 transmembrane domains.

The Binding Activity of HTR1B (7TM) with GSTK1 Activity: Measured by its binding ability in a functional ELISA. Immobilized HTR1B at 5 μg/ml can bind human GSTK1, the EC50 of human GSTK1 protein is 159.40-218.50 ng/ml.