Question

The results of the experiment performed in the passage, and the model proposed in response, suggest that what relationship exists between the surface activity of mutant proteins and the relaxation of wrinkles under compression in the protein film?
A. The surface activity of the monomers is decreased in each mutant protein, allowing release of the monomers from the interface.

B. Compression increases the attractive forces between water molecules and portions of Bs1A monomers, contributing to release of the monomers from the interface.

C. Wrinkle formation increases the surface activity in mutant proteins, causing release of the monomers from the interface.

D. Decreased surface activity of mutant protein leads to compression in the protein film, causing release of monomers from the interface.

Answer 1

The surface activity of the monomers is decreased in each mutant protein, allowing release of the monomers from the interface.

Explanation:

Compression of the film is a consequence of withdrawal of protein solution from the droplet during step 2 of the pendant droplet test.

This is shown by the folds in the region around the dropping collar, which can be seen more distinctly after a more liquid retraction.

The wrinkles of the protein film analysis revealed that there has been no relaxation for 10 minutes after compression, which means that this surface layer is stable. Such findings show that BslA can self-assemble into a stable and complex superior film without the help of a protein or carbohydrate partner.