Sandbox 43: Difference between revisions
No edit summary |
No edit summary |
||
| Line 9: | Line 9: | ||
== '''Structure''' == | == '''Structure''' == | ||
The quaternary structure of horse pancreatic lipase (as featured right) contains two molecules which each contain 449 amino acid residues, 705 water molecules, and | The quaternary structure of horse pancreatic lipase (as featured right) contains two molecules which each contain 449 amino acid residues, 705 water molecules, and 1 calcium ion. These two identical molecules are connected by a two-fold symmetry axis. The <scene name='Sandbox_43/Interactions_between_chains/1'>interactions between the a chain and the b chain</scene> include hydrogen bonds and salt bridges. The secondary structure of lipase is composed of 102 residues that constitute 13 <scene name='Sandbox_43/Alpha_helixes/1'>alpha helices</scene> (22% helical) and 139 residues that constitute 28 <scene name='Sandbox_43/Beta_sheets/3'>beta sheet</scene> strands (30% beta sheets). Lipase is essentially composed of two domains, the <scene name='Sandbox_43/N_terminal/1'>N-terminal domain</scene>, which contains the <scene name='Sandbox_43/Active_site/4'>active site</scene> of lipase (consisting of three residues: Ser-152, Asp-176, and His-263). The N-terminal domain also contains the <scene name='Sandbox_43/Active_site/3'>lid region</scene> (residues 216-239) which serves to block the active site, which is nestled in the <scene name='Sandbox_43/Hydrophobic/2'>hydrophobic regions</scene>, from the solvent. Additionally, the <scene name='Sandbox_43/C_terminal/1'>C-terminal domain</scene> is essential to the binding of lipase with colipase, an important cofactor for the catalysis of lipids. This forms the <scene name='Sandbox_43/Complex_with_colipase/1'>lipase-colipase complex</scene>. | ||
== '''Calcium Ligand''' == | == '''Calcium Ligand''' == | ||
The most prominent ligand involved in the structure of lipase is the <scene name='Sandbox_43/Calcium_ligand/3'>calcium ion</scene>. This ion has been shown to promote the folding of lipase into its active dimer state. As such, the calcium ion is extremely important in forming the lipase-fat complex, necessary for the breakdown of lipids. Studies have shown that an increase in calcium concentration in a lipase catalyzed reaction resulted in an increase in the rate of the reaction. | The most prominent ligand involved in the structure of lipase is the <scene name='Sandbox_43/Calcium_ligand/3'>calcium ion</scene>. This ion has been shown to promote the folding of lipase into its active dimer state. As such, the calcium ion is extremely important in forming the lipase-fat complex, necessary for the breakdown of lipids. Studies have shown that an increase in calcium concentration in a lipase catalyzed reaction resulted in an increase in the rate of the reaction. | ||
Revision as of 21:38, 13 November 2011
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.
Horse Pancreatic LipaseIntroduction<StructureSection load='1hpl' size='500' side='right' caption='Structure of Horse Pancreatic Lipase (PDB entry 1hpl)' scene=>A subclass of esterases, pancreatic lipase (EC 3.1.1.3) is an enzyme that catalyzes the hydrolysis and formation of lipids. While produced in the pancreas, it is also present in the stomach and mouth. Due to its effective ester bond hydrolysis of lipids, lipase is essential for fat digestion, breaking lipids into monoglycerides and single fatty acids. If one is lipase deficient, it is hard to obtain adequate nutrition from food. This results in diseases such as cystic fibrosis, Crohn's disease, and celiac disease. StructureThe quaternary structure of horse pancreatic lipase (as featured right) contains two molecules which each contain 449 amino acid residues, 705 water molecules, and 1 calcium ion. These two identical molecules are connected by a two-fold symmetry axis. The interactions between the a chain and the b chain include hydrogen bonds and salt bridges. The secondary structure of lipase is composed of 102 residues that constitute 13 alpha helices (22% helical) and 139 residues that constitute 28 beta sheet strands (30% beta sheets). Lipase is essentially composed of two domains, the N-terminal domain, which contains the active site of lipase (consisting of three residues: Ser-152, Asp-176, and His-263). The N-terminal domain also contains the lid region (residues 216-239) which serves to block the active site, which is nestled in the hydrophobic regions, from the solvent. Additionally, the C-terminal domain is essential to the binding of lipase with colipase, an important cofactor for the catalysis of lipids. This forms the lipase-colipase complex. Calcium LigandThe most prominent ligand involved in the structure of lipase is the calcium ion. This ion has been shown to promote the folding of lipase into its active dimer state. As such, the calcium ion is extremely important in forming the lipase-fat complex, necessary for the breakdown of lipids. Studies have shown that an increase in calcium concentration in a lipase catalyzed reaction resulted in an increase in the rate of the reaction. |
