Universitas Indonesia 2021 iGEM team created a project focused on H pylori
eradication treatment using an engineered E. coli Nissle
1917. We use several parts for our project, including Proteinase K and copA promotor. We chose Proteinase K because it has the activity to degrade biofilms of microorganisms, including H pylori
which is the target of our project. CopA promoter is used to induce the downstream gene expression for the kill switch system using ammonia. Due to the COVID-19 restriction, we can't do experiments in the lab, so we contributed to those parts documentation through literature studies and got the following results.
Proteinase K (BBa_K1149035
) has the catalytic triad (active site) at Asp 39, His 69, and Sr224. The optimum pH range for maximal activity of Proteinase K is 7.5–12.01
. In addition, Ca2+
ions have a role in providing protection against autolysis and increasing the thermal stability of proteinase K2
. As we mentioned before, Proteinase K can inhibit biofilm formation and degrade preformed biofilm of H. Pylori3
. CopA promoter (BBa_K1555000
) usually can sense copper, but our literature study reported that copA promoter also could sense gold and ammonia for promoter activation4-5
. For further information and characterization, you can check it at this link BBa_K1149035
Hopefully, the information we provide can be used as a reference parameter for the use of parts so that experiments carried out in the future can increase the chances of success.
- Barret A, Rawlings N, Woessner J. Handbook of Proteolytic Enzymes. 3rd ed. Academic Press. 2012
- Bajorath J, Hinrichs W, Saenger W. The enzymatic activity of proteinase K is controlled by calcium. Eur J Biochem. 1988;176(2):441–7.
- Windham I, Servetas S, Whitmire J, Pletzer D, Hancock R, Merrell D. Helicobacter pylori Biofilm Formation Is Differentially Affected by Common Culture Conditions, and Proteins Play a Central Role in the Biofilm Matrix. Applied and Environmental Microbiology. 2018;84(14)
- Stoyanov J, Brown N. The Escherichia coli Copper-responsivecopA Promoter Is Activated by Gold. Journal of Biological Chemistry. 2003;278(3):1407-1410.
- 5. Shen P, Niu D, Permaul K, Tian K, Singh S, Wang Z. Exploitation of ammonia-inducible promoters for enzyme overexpression in Bacillus licheniformis. Journal of Industrial Microbiology and Biotechnology. 2021;48(5-6):1-8.