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Sandbox 47
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== '''Introduction''' == | == '''Introduction''' == | ||
Pancreatic <scene name='Sandbox_47/Lipase/1'>lipase</scene> (EC 3.1.1.3) is secreted from the pancreas and is the primary enzyme that breaks down lipids in the digestive system. It converts triglyceride substrates to monoglycerides and free fatty acids. <ref>"Pancreatic lipase". Wikipedia: The Free Encyclopedia. 7 Nov 2011 [http://en.wikipedia.org/wiki/Pancreatic_lipase]</ref> | Pancreatic <scene name='Sandbox_47/Lipase/1'>lipase</scene> (EC 3.1.1.3) is secreted from the pancreas and is the primary enzyme that breaks down lipids in the digestive system. It converts triglyceride substrates to monoglycerides and free fatty acids. <ref>"Pancreatic lipase". Wikipedia: The Free Encyclopedia. 7 Nov 2011 [http://en.wikipedia.org/wiki/Pancreatic_lipase]</ref> | ||
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== '''Structure''' == | == '''Structure''' == | ||
The structure of human pancreatic lipase has been solved, but a refined version has not been published. Horse pancreatic lipase, on the other hand, has been solved and published. Horse pancreatic lipase (PDB ID 1hpl) consists of 449 amino acids and 705 well-defined water molecules in two subunits, <scene name='Sandbox_47/Lipasechaina/2'>A</scene> and <scene name='Sandbox_47/Lipasechainb/1'>B</scene>. Its <scene name='Sandbox_47/Lipasesecondarystructures/1'>secondary structure</scene> consists of 22% <scene name='Sandbox_47/Lipase_helix/2'>helices</scene> and 30% <scene name='Sandbox_47/Lipase_sheet/2'>beta sheets</scene>. Lipase also binds two <scene name='Sandbox_47/Lipase_calcium/2'>calcium ions</scene> as ligands. It contains both <scene name='Sandbox_47/Lipase_hydrophobicres/2'>hydrophobic</scene> and <scene name='Sandbox_47/Lipase_polarres/1'>polar residues</scene>. The overall molecular structure of horse lipase has two well-defined domains.The N-terminal domain contains the active site and has a typical alpha/beta hydrolase fold topology. The C-terminal domain, for colipase binding, has a beta-sheet sandwich topology.<ref>Bourne Y, Martinez C, Kerfelec B, Lombardo D, Chapus C, Cambillau C. 1994. Horse pancreatic lipase. J. mol Biol. 238: 709-732.</ref> | The structure of human pancreatic lipase has been solved, but a refined version has not been published. Horse pancreatic lipase, on the other hand, has been solved and published. Horse pancreatic lipase (PDB ID 1hpl) consists of 449 amino acids and 705 well-defined water molecules in two subunits, <scene name='Sandbox_47/Lipasechaina/2'>A</scene> and <scene name='Sandbox_47/Lipasechainb/1'>B</scene>. Its <scene name='Sandbox_47/Lipasesecondarystructures/1'>secondary structure</scene> consists of 22% <scene name='Sandbox_47/Lipase_helix/2'>helices</scene> and 30% <scene name='Sandbox_47/Lipase_sheet/2'>beta sheets</scene>. Lipase also binds two <scene name='Sandbox_47/Lipase_calcium/2'>calcium ions</scene> as ligands. It contains both <scene name='Sandbox_47/Lipase_hydrophobicres/2'>hydrophobic</scene> and <scene name='Sandbox_47/Lipase_polarres/1'>polar residues</scene>. The overall molecular structure of horse lipase has two well-defined domains.The N-terminal domain contains the active site and has a typical alpha/beta hydrolase fold topology. The C-terminal domain, for colipase binding, has a beta-sheet sandwich topology.<ref>Bourne Y, Martinez C, Kerfelec B, Lombardo D, Chapus C, Cambillau C. 1994. Horse pancreatic lipase. J. mol Biol. 238: 709-732.</ref> | ||
| - | == '''Function''' == | ||
| - | Most lipases act at a specific position on the glycerol backbone of the lipid substrate.<ref>"Lipase". Wikipedia: The Free Encyclopedia. 6 Nov 2011 [http://en.wikipedia.org/wiki/Lipase]</ref> | ||
| + | == '''Function''' == | ||
| + | Most lipases act at a specific position on the glycerol backbone of the lipid substrate.<ref>"Lipase". Wikipedia: The Free Encyclopedia. 6 Nov 2011 [http://en.wikipedia.org/wiki/Lipase]</ref> Bile salts aid lipase in fat hydrolysis by increasing the surface area of fats. | ||
Unlike many proteases, pancreatic lipase is secreted in its final form. However, it is only active in the presence of colipase in the duodenum. Colipase is also secreted in the pancreas, but in its inactive form, procolipase, which is activated by trypsin in the intestinal lumen. Colipase prevent the inhibitory effect of bile salts on the lipase-catalyzed intraduodenal hydrolysis of dietary long-chain triglycerides.<ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref> | Unlike many proteases, pancreatic lipase is secreted in its final form. However, it is only active in the presence of colipase in the duodenum. Colipase is also secreted in the pancreas, but in its inactive form, procolipase, which is activated by trypsin in the intestinal lumen. Colipase prevent the inhibitory effect of bile salts on the lipase-catalyzed intraduodenal hydrolysis of dietary long-chain triglycerides.<ref>"Colipase". Wikipedia: The Free Encyclopedia. 5 July 2011 [http://en.wikipedia.org/wiki/Colipase]</ref> | ||
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== '''References''' == | == '''References''' == | ||
Revision as of 05:40, 10 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. |
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