Sandbox 35
From Proteopedia
| Line 19: | Line 19: | ||
<applet load='3IJU' size='350' frame='true' align='right' caption='Basic Structure of HEW Lysozyme.' /> | <applet load='3IJU' size='350' frame='true' align='right' caption='Basic Structure of HEW Lysozyme.' /> | ||
HEW Lysozyme is a small enzyme, weighing 14.3 kD and containing only 129 amino acid residues. From his determination of the structure, Phillips found that lysozyme had an ellipsoidal shape and a prominent cleft which acted as the sustrate-enzyme binding site. This <scene name='Sandbox_35/Cleft/1'>cleft</scene> can be seen best when looking at a surface view of the protein. The two amino acids that most directly interact with the substrate when cutting glycosidic bonds are | HEW Lysozyme is a small enzyme, weighing 14.3 kD and containing only 129 amino acid residues. From his determination of the structure, Phillips found that lysozyme had an ellipsoidal shape and a prominent cleft which acted as the sustrate-enzyme binding site. This <scene name='Sandbox_35/Cleft/1'>cleft</scene> can be seen best when looking at a surface view of the protein. The two amino acids that most directly interact with the substrate when cutting glycosidic bonds are | ||
| - | <scene name='Sandbox_35/Asp_52_and_gln_57/1'>Gln 57 and Asp 52</scene>. | + | <scene name='Sandbox_35/Asp_52_and_gln_57/1'>Gln 57 and Asp 52</scene> (Gln is blue and Asp is purple). |
=== Secondary Structures === | === Secondary Structures === | ||
| Line 27: | Line 27: | ||
<scene name='Sandbox_35/2ndary_structure/5'>secondary structure</scene> | <scene name='Sandbox_35/2ndary_structure/5'>secondary structure</scene> | ||
| - | + | === Intermolecular Forces === | |
| - | === | + | <scene name='Sandbox_35/Next_attempt/1'>backbone disulfide bonds</scene> |
| + | <scene name='Sandbox_35/Next_attempt/3'>side chain disulfide bonds</scene> | ||
| + | |||
| + | <scene name='Sandbox_35/Next_attempt/4'>hydrogen bonds between backbone</scene> | ||
| + | <scene name='Sandbox_35/Next_attempt/5'>hydrogen bonds between side chains</scene> | ||
== Catalytic Reaction == | == Catalytic Reaction == | ||
Revision as of 04:53, 30 October 2010
| 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. |
Contents |
Lysozyme - Hen Egg White (HEW)
Lysozyme is an enzyme that breaks down cell walls by hydrolyzing certain glycosidic linkages in the peptidoglycan of cell walls. It is found in the cells and secretions of various vertebrates, and likely functions as an bacteria-killing or -disposal agent. The lysozyme found in hen egg white has been investigated more thoroughly than other species of lysozyme, and so is better understood then most enzymes.[1] The PDB code of HEW lysozyme shown on this page is 3IJU and the assigned EC number for lysozyme is EC 3.2.1.17.
History
The enzyme Lysozoyme was first discovered and named in 1922 by Alexander Fleming. Fleming contaminated petri plates containing gram-positive bacteria with nasal mucous. After this contamination, he found that the bacterial cells on the petri plates had been lysed. He continued to investigate the cause of the cell lysis, and discovered lysozyme.[2] He also discovered that lysozyme only works on gram-positive cells, and not on gram-negative cells. Gram-negative cells have an outer cell membrane containing lipopolysaccharides, which cannot be digested by lysozyme.[3] Gram-positive cells, however, do not have this outer membrane, and so can be lysed by lysozyme.
The structure of HEW Lysozyme was investigated and found out in 1965 by David Phillips, making it the first enzyme to have its structure determined. Phillips initially elucidated the structure through X-Ray crystallography and then continued his investigation of substrate binding by building models of the enzyme.It was through this larger-scale model building that Phillips was able to identify the catalytic site of lysozyme.[4]
Structure
Basics
|
HEW Lysozyme is a small enzyme, weighing 14.3 kD and containing only 129 amino acid residues. From his determination of the structure, Phillips found that lysozyme had an ellipsoidal shape and a prominent cleft which acted as the sustrate-enzyme binding site. This can be seen best when looking at a surface view of the protein. The two amino acids that most directly interact with the substrate when cutting glycosidic bonds are (Gln is blue and Asp is purple).
Secondary Structures
Intermolecular Forces
Catalytic Reaction
Mechanism
Current Uses
References
- ↑ Voet, D., Voet, J., Pratt, C.(2008) Fundamentals of Biochemistry: Life at the Molecular Level, 3rd edition. John Wiley and Sons, Inc.
- ↑ copyright 2006-2008. http://lysozyme.co.uk/
- ↑ http://en.wikipedia.org/wiki/Gram-negative_bacteria
- ↑ Voet, D., Voet, J., Pratt, C.(2008) Fundamentals of Biochemistry: Life at the Molecular Level, 3rd edition. John Wiley and Sons, Inc.
