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Part:BBa_K3185003
SPYCatcher
Usage and Biology
SpyCatcher is a protein that came from the CnaB2 domain of FbaB, Streptococcus pyogenes(SpyCatcher:BBa_K1159200). In a natural environment, CnaB2 domain is used for attaching to host cells. In a paper, it is partially changed and divided into two domains.[1]
Nowadays, these two protein domains are known as SpyCatcher/SpyTag system because they bind irreversibly with a covalent bond.
In our experiment, we used the SpyCatcher/SpyTag system and designed only SpyCatcher part for assay(SpyCatcher:BBa_K1159200, SpyTag:BBa_K1159201). In addition, this has two tag or cleavage sites. First is 6×His-tag inserted in the N-terminus of SpyC for protein purification. Second is a TEV protease site because, in the paper, it was used for protein purification[2]. However, we didn’t use it in our experiment.
We put it between the BamHI site and the Ndel site on pET11-a. We used BL21 (DE3) for gene expression. We used the Ni-NTA agarose for purification. After that, we confirmed the molecular weight of SpyCatcher by using SDS-PAGE.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Purification
Expression
- Cells were grown in 200ml LB media (100μg/ml Ampicillin) at 37oC shaking at 140 rpm to an OD600 of 0.5, verifying via a spectrophotometer.
- Protein was expressed in 0.1mM IPTG for 2hours.
SDS-PAGE
Result
![](/wiki/images/f/f1/191008_Dot_Blot.png)
A 3µL of protein solution dropped on PET film, then left for 20min. Then the film was washed in TBST for 5min x3, then placed with Anti-His-tag-HRP conjugated for 1h. ECL substrate was added, then chemiluminescence was imaged by LAS-3000. The exposure time is 6min.
References
1 Zakeri, B., Fierer, J.O., Celik, E., Chittock, E.C., Schwarz-Linek, U., Moy, V.T., and Howarth, M. (2012).
Peptide tag forming a rapid covalent bond to a protein, through engineering a bacterial adhesin.
Proc. Natl. Acad. Sci. U. S. A. <i>109.
2 Veggiani, G., Nakamura, T., Brenner, M.D., Gayet, R. V., Yan, J., Robinson, C. V., and Howarth, M. (2016).
Programmable polyproteams built using twin peptide superglues.
Proc. Natl. Acad. Sci. U. S. A.
113, 1202–1207.
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