It breaks down the cysteine units into the two individual cysteine amino acids, as we'll see in just a moment. So together, these two agents can be used to denature to break down the tertiary and secondary structure of our protein. Now, the next question is, what protein did Christian actually use? Well, Christian used a ribonuclease, which is basically an enzyme of protein that catalyzes the breaking down of RNA molecules in the cells of organisms. And this particular protein has 124 amino acids in its primary sequence. And in the tertiary structure, it contains four individual disulfide bonds.