Sandbox 43
From Proteopedia
(Difference between revisions)
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== '''Structure''' == | == '''Structure''' == | ||
| - | The <scene name='Sandbox_43/Quat_struc/2'>quaternary structure</scene> of horse pancreatic lipase 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 tertiary structure of lipase is stabilized by <scene name='Sandbox_43/Disulfide/1'>disulfide bonds</scene> between cysteine residues. The <scene name='Sandbox_43/Interactions_between_chains/1'>interactions between the a chain and the b chain</scene> include <scene name='Sandbox_43/Hydogen_bonds/1'>hydrogen bonds</scene> 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).<ref>http://www.pdb.org/pdb/explore.do?structureId=1HPL</ref> Lipase is essentially composed of two domains, as shown in the N-terminus to C-terminus <scene name='Sandbox_43/N-c_rainbow/1'>rainbow depiction</scene>. The <scene name='Sandbox_43/N_terminal/1'>N-terminal domain</scene>, which contains the <scene name='Sandbox_43/Active_site/8'>active site</scene> of lipase (consisting of three residues: Ser-152, Asp-176, and His-263).<ref>http://www.nature.com/nature/journal/v343/n6260/abs/343771a0.html</ref> 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/Hhhhhhhhhhhyrdop/1'>hydrophobic regions</scene>, (in red) from the solvent. Likewise, the active site does not have interactions with the polar, <scene name='Sandbox_43/Hhhhhyrdophilic/1'>hydrophilic regions</scene> (in orange). 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> pictured also with the triglyceride in the substrate binding site. | + | The <scene name='Sandbox_43/Quat_struc/2'>quaternary structure</scene> of horse pancreatic lipase 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 tertiary structure of lipase is stabilized by <scene name='Sandbox_43/Disulfide/1'>disulfide bonds</scene> between cysteine residues. The <scene name='Sandbox_43/Interactions_between_chains/1'>interactions between the a chain and the b chain</scene> include <scene name='Sandbox_43/Hydogen_bonds/1'>hydrogen bonds</scene> 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).<ref>http://www.pdb.org/pdb/explore.do?structureId=1HPL</ref> Lipase is essentially composed of two domains, as shown in the N-terminus to C-terminus <scene name='Sandbox_43/N-c_rainbow/1'>rainbow depiction</scene>. The <scene name='Sandbox_43/N_terminal/1'>N-terminal domain</scene>, which contains the <scene name='Sandbox_43/Active_site/8'>active site</scene> of lipase (consisting of three residues: Ser-152, Asp-176, and His-263).<ref>http://www.nature.com/nature/journal/v343/n6260/abs/343771a0.html</ref> 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/Hhhhhhhhhhhyrdop/1'>hydrophobic regions</scene>, (in red) from the solvent. Likewise, the active site does not have interactions with the polar, <scene name='Sandbox_43/Hhhhhyrdophilic/1'>hydrophilic regions</scene> (in orange). 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> pictured also with the triglyceride in the substrate binding site.<ref>http://en.wikipedia.org/wiki/Colipase</ref> |
== '''Calcium Ligand''' == | == '''Calcium Ligand''' == | ||
[[Image:Diag calcium 2.gif|150px|right|thumb| Calcium Ion <ref>http://www.bbc.co.uk/schools/gcsebitesize/science/images/diag_calcium_2.gif</ref>]] | [[Image:Diag calcium 2.gif|150px|right|thumb| Calcium Ion <ref>http://www.bbc.co.uk/schools/gcsebitesize/science/images/diag_calcium_2.gif</ref>]] | ||
| - | The most | + | The most significant ligand involved in the structure of lipase is the <scene name='Sandbox_43/Calcium_ligand/3'>calcium ion</scene>.<ref>http://www.sciencedirect.com/science/article/pii/S0268005X10000561</ref> This ion has been shown to promote the folding of lipase into its active dimer state, keeping in that state throughout the course of the lipase's hydrolysis of fat. As such, the calcium ion is extremely important in forming the lipase-fat complex, evidently necessary for the breakdown of lipids. Studies have shown that an increase in calcium concentration in a lipase catalyzed reaction results in an increase in the rate of the reaction, demonstrating the acute importance of the calcium ion. Furthermore, other ions such as magnesium have been tested and have been shown to not promote the folding of lipase into its dimer state, indicating the specificity of calcium in lipase.<ref>http://jb.oxfordjournals.org/content/72/6/1565.extract</ref> |
== '''Colipase Cofactor''' == | == '''Colipase Cofactor''' == | ||
Revision as of 02:28, 14 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. |
Pancreatic Lipase
Introduction
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