Molecule, Protein Denaturing Proteins with DTT
The structure is shown below, explain how this molecule will denature proteins and state. What specific amino acid linkages would be interrupted. First thing you should remember or understand, is what a tertiary structure of a protein is. The tertiary structure refers to the spatial arrangement of amino acid residues that are far apart in the sequence and to the pattern of its disulfide bonds. In other words, this is how the r groups of the peptide chain interact with one another and causes the main chain to fold onto itself. What that would look like is you: have you have a peptide sequence of amino acids and theyre all folded and wrapped onto each other, and what causes this tertiary structure is when you have disulfide bonds? Okay lets just put some disulfide bonds in here and theyre random, but they cause that peptide chain to fold onto itself, giving it its 3d structure and also giving it its activity. Okay, and when youre denaturing a tertiary structure or denaturing a protein denaturing. A protein is when the three dimensional structure or shape is destroyed or converted into a randomly coiled peptide without its normal activity. How are these disulfide bonds created or what is a disulfide bond? A disulfide bond is when two sulfur atoms are oxidized and create a bond between the two atoms, all right so which amino acids have sulfur and which amino acid creates disulfide bonds. Methionine has sulfur, but it does not create disulfide bonds cysteine.
On the other hand, cysteine has sulfur in its r group, and it is the amino acid that creates im messing up here and it creates the disulfide bond. Okay, so here is the sulfur. We need to create a disulfide bond. Okay and a disulfide bond is when two cysteines come together and create and they are oxidized and create a bond together. Okay, so lets look at it like this, so you have sulfur. It lost its hydrogen, okay and now youre going to create this bond between each other. That is a disulfide bond. Okay. Now what happens? Is this molecule? Dtt will come in and interrupt this disulfide bond by donating hydrogens to each one of these sulfurs reducing the disulfide bond, and so instead of a disulfide bond, you will actually have a hydrogen here and then that causes the protein to denature, because where those disulfide bonds Were before holding in this image in its shape, let me draw this in a better spot, holding it in its shape. Now what you have is reduce sulfurs and now this can actually come apart. It will which we call denaturing. We call that denaturing.