Sandbox 34
From Proteopedia
| Please do NOT make changes to this Sandbox. Sandboxes 30-60 are reserved for use by Biochemistry 410 & 412 at Messiah College taught by Dr. Hannah Tims during Fall 2012 and Spring 2013. |
Lysozyme
Lysozyme is an amazingly effective enzyme known for its catalytic activity of lysing bacterial cell walls. Lysozyme is effective at this through its ability to hydrolyze the 1,4 beta-linkages from the N-acetylmuramic acid to the N-acetylglucosamine residues in bacterial cell walls. Lysozyme also contains a unique ability to hydrolyze the bonds in chitin, which can be found in things like tough outer exoskeletons in crustaceans and in fungi.
We are most familiar with lysozyme's powerful antibacterial character as is seeks to attack peptidoglycans within the cell walls of most Gram-positive bacteria. It is because of this ability that we find lysozyme as a part of the innate immune in the human body as one of the first defenses towards warding off infections. We can find them also externally in such secretions for the same reasons such as saliva and tears.
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Lysozyme's Secondary Structures
Lysozyme is a small but complex structure that utilizes all of its resources in its. Lysozyme contains both five alpha helices as well as five beta sheets. As the structures can be seen, the alpha helices (in the pink), are grouped together fairly tightly while the majority of three out of the five beta sheets (the yellow arrows), group with themselves. The two other beta sheets are paired off together separately on the other side as you can observe. The beta sheets as seen bind very tightly as they line up directly next to each other as a result of their anitparallel motif. This allows them to maximize their hydrogen bonding while still staying free of torsional and steric strains.
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Protein Folding
Lysozyme’s unique tertiary structure resides from the strong forces that regulate is folding. It is because lysozyme contains both hydrophobic (water hating) and hydrophilic (water loving) regions that it is controlled by the hydrophobic effects and is driven by hydrophobic collapse. This major driving force referred to as hydrophobicity requires the hydrophobic regions that cannot interact with water to be driven into the internal core of the protein so that it is shielded from all water molecules. This leaves the entire outside of the protein to be comprised of its hydrophilic regions, which are free to interact with all the water molecules the protein encounters in solution.
As seen to the right, they hydrophobic regions can be observed by looking at the differences between the two colors on the protein structure. You can notice that the gray colors represent the hydrophobic regions as they remain tucked away on the inside of the protein. Incasing them would be the hydrophilic regions that surround the protein and are represented by the purple color.
