Part:BBa_K3117030
scFv against CD3 with SpyTag codon optimized for CHOs
BBa_K3117026 is a fusion protein of an anti-CD3 single-chain variable fragment (scFv) and SpyTag (BBa_K3117015).
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal XhoI site found at 604
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Characterization and measurement
The construct 2b (K2b) was synthesized by IDT. It was cloned into the expression vector pSEC/tag2/Hygro\C\-\OK by Gibson Assembly. Our protein was under control of the CMV promotor ensuring a high-level constitutive expression. Afterwards, the construct was brought into HEK293T cells with either calcium phosphate transfection or lipofection.
The accuracy of the inserted DNA after cloning was confirmed with sequencing. The data is depicted in Fig. 1.
Bild Sequencing K2b
Figure 1: Sequencing data of the complete K2b
Fig. 2 shows the harvest after transfection into HEK 293T cells in a western blot. For detection, the His-Tag in the K2b sequence (BBa_K3117005) provides the opportunity to be used as a target for a primary antibody in a western blot. K2b can be seen at expected height (41 kDa). Presence of K2b in the medium proves the function of the Igk leader (BBa_K3117006), which is directing the protein into the secretory pathway.
Bild Ernte Figure 2: Western blot of the harvest after transfection into HEK 293T cells with an anti-His-Tag antibody
Furthermore the His-Tag (BBa_K3117005) in K2b allows purification of the protein with HisTrap columns. The western blot after this purification is shown in Fig. 3, showing the remaining presence of the protein after this step.
Bild Aufreinigung Figure 3: Western blot of the purified protein with HisTrap columns with an anti-His_tag antibody
For the SpyTag/SpyCatcher reaction the protein K2b was added to the protein K2a (BBa_K3117026). A height of 83 kDa was expected in the afterwards performed western blot, depicted in Fig 4. A specific band appeared after adding the two products, but this band was running at ~120 kDa. This size could be explained by formation of trimeric protein (Schoene, Fierer, Bennett, & Howarth, 2014).
Bild TagCatcher Figure 4: Western blot after SpyTag/SpyCatcher reaction
References
1. Hatlem, D., Trunk, T., Linke, D., & Leo, J. C. (2019). Catching a SPY: Using the SpyCatcher-SpyTag and Related Systems for Labeling and Localizing Bacterial Proteins. International journal of molecular sciences, 20(9), 2129.
2. Rageul, J., Mottier, S., Jarry, A., Shah, Y., Théoleyre, S., Masson, D., . . . Denis, M. G. (2009). KLF4‐dependent, PPARγ‐induced expression of GPA33 in colon cancer cell lines. International journal of cancer, 125(12), 2802-2809.
3. Schoene, C., Fierer, J. O., Bennett, S. P., & Howarth, M. (2014). SpyTag/SpyCatcher cyclization confers resilience to boiling on a mesophilic enzyme. Angewandte Chemie International Edition, 53(24), 6101-6104.
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