What happens when you tag a protease with its own degradation tag?

Question

I've been learning about the ClipXP, ClipAP, and Lon proteases. They are proteases from the AAA+ family, which seek out proteins tagged with certain peptide sequences, unfold them, and chop them up.

But what happens when you tag a protease with its own degradation tag? For example, what if you took DNA encoding mf-Lon and added its ssrA tag to the end, and then expressed this sequence in bacteria?

Would this result in any interesting dynamics? Will the protease start trying to degrade itself like an Ouroboros? Will it get stuck trying to do so? Will we observe any interesting dynamics when we incorporate this into a gene circuit?

acvill · Answer

The process of self-degradation of a protease is called autolysis, and the rate of autolysis depends on many factors including temperature, pH, and enzyme concentration.1,2 While most proteases show reduced proteolytic activity with increased autolysis, some proteases demonstrate increased activity after they are self-hydrolyzed. The most notable example is trypsinogen, which, when cleaved initially by enteropeptidase, yields trypsin, an important digestive enzyme. Trypsin can then hydrolyze more trypsinogen molecules in a process known as autocatalysis / autoactivation.3

References

Chen XL, Shun CY, Zhang YZ, Gao PJ. Rapid monitoring of autolysis process of proteases by capillary electrophoresis. Biotechnol Lett. 2003 Oct;25(20):1763-7.
Khalil ME, Metwalli SM, El-Sebaiy LM. Factors affecting the autolysis rate of crude preparations of proteolytic enzymes from Bouri fish (Mugil cephalus). Food Chem. 1987, 24, 127-135.
Mayer J, Rau B, Schoenberg MH, Beger HG. Mechanism and role of trypsinogen activation in acute pancreatitis. Hepatogastroenterology. 1999 Sep-Oct;46(29):2757-63.

What happens when you tag a protease with its own degradation tag?

One Answer

Add your own answers!

Ask a Question