Question

You want to artificially produce an enzyme, protein A. through genetic-engineering. Although can get your "engineered" bacteria to produce large quantities of A, the product is insoluble and inactive. Which of the following procedures might be worth trying to obtain a soluble and active enzyme (multiple correct answers are possible) a) Make the bacteria produce A at a lower rate and in smaller amounts b) Dissolve the protein aggregate in urea, dilute and remove the urea c) Treat the insoluble aggregate with a protease. d) Make the bacteria produce chaperone proteins in addition to A.

Answer 1

Option D is correct. Chaperones are group of proteins which assist proteins for completion of their folding stages. In general, newly synthesized proteins are linear and may be insoluble and inactive which become active with the help of chaperones by attaining their folding stages during post translational modification. Some bacteria produces inactive, impure and insoluble proteins due to lack of production of chaperones like Hsp70 or Hsp40. In this condition researchers are suggested to use the engineered host system.

Urea can dissolve the protein precipitates but cannot make enzyme active. The activity of enzymes attained only by the proper folding of proteins which is only possible with chaperones. Hence option b is not suitable.