Lysozymes
In
order to explore protein structures I went onto a protein model visualizer, called
Jolecule, on http://jolecule.appspot.com/. Once on the main page, I clicked on the “myoglobin”
button, and then the “garden” link in the upper right corner. This last link brought me to a variety of
proteins to select from and learn about.
After I have looked through them, I chose to research the Lysozyme
protein.
Lysozymes
are small protein enzymes that bind to polysaccharide chains and break them
apart by hydrolysis. These enzymes protect
humans from danger of bacterial infection by attacking and destroying the cell
walls of the bacteria. The bacteria
itself constructs a tough skin of carbohydrate chains (sugars) that are interconnected
by short peptide strands. In order to
fight the bacteria, the lysozyme breaks the carbohydrate chains of the
bacteria, which in turn, destroys the structural integrity of the cell wall and
causes the bacteria to burst. However,
as efficient as it is in killing bacteria, the lysozyme is too large of a
molecule to travel between cells, that it cannot rid the entire body of
disease. Lysozymes occur in plant and
animal tissues and in secretions such as tears, saliva and mucus. Also it is greatly found in egg whites. It is found in our tears, and mucus to resist
infection on exposed surfaces. Lysozyme
also provides protection in the blood because blood is the worst place for
bacteria to grow. In general Lysozymes
protect many places that are rich in potential food for bacteria. As well, Lysozyme is added to digest cell
debris and release the inclusion bodies.
Furthermore, Lysozyme is a crystal structure with two structural domains. One is made up of mainly alpha helices, and
the other is mainly beta strands. The
boundary between the two domains forms a split where the substrate binds. Lysozyme adds a molecule of water to the bond
between two sugars, which breaks the bond.
This is catalyzed by two amino acid side chains in the active site of
the enzyme. These active sites are
glutamate 35 and aspartate 52.
 |
| - This is the overall picture of the lysozyme protein with the polysaccharide substrate in the center. |
.JPG) |
| - This is one of the glu-35 active sites of the enzyme, which would lie next to the polysaccharide. |
.JPG) |
| - This is one of the asp-52 active sites of the enzyme, which would lie next to the polysaccharide. |
This is a very informative article. I think that probably instead of referring to the lysozyme as a crystal structure, it would be a tertiary structure since it is made up of alpha helices and beta sheets.
ReplyDeleteThank you for your comments. You are correct that it is a tertiary structure, I will correct it in the article.
DeleteThank you for your comments. You are correct that it is a tertiary structure, I will fix this in the article.
Delete