Sandbox 40
From Proteopedia
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=The Mechanism= | =The Mechanism= | ||
[[Image:Hydrolysis of trigly.png|200px|left|thumb| This is the reaction catalyzed by most lipases. Shown is a triglyceride being hydrolyzed by water, resulting in glycerol and three liberated fatty acids. Pancreatic Lipase, however, only hydrolyzes two ester bonds from triglycerides.]] Lipase works with a substrate that consists usually of triglycerides. Triglycerides are composed of glycerol connected via ester bonds to three fatty acids. These molecules are split by hydrolysis (see figure). This is the reaction catalyzed by most lipases. Lipase acts on the exterior fatty acids of triglycerides, hydrolyzing the bonds and freeing the two outer fatty acids from the glycerol backbone. The <scene name='Sandbox_40/Active_site/1'>active site</scene> of lipase consists mainly of three residues. These three residues are SER152, ASP176, and HIS263. The mechanism for these hydrolysis reactions begins with SER152 attacking a carbonyl carbon, forming a tetrahedral intermediate. When the oxyanion reforms its double bonded form, the oxygen originally from the ester bond acts as the leaving group and accepts a hydrogen from HIS263. Next, water is converted into a nucleophile by donating a hydrogen to the HIS263, then attacking the new carbonyl. The SER152 now acts as the leaving group, producing a fatty acid chain which has been separated from glycerol and regenerating the enzyme active site. | [[Image:Hydrolysis of trigly.png|200px|left|thumb| This is the reaction catalyzed by most lipases. Shown is a triglyceride being hydrolyzed by water, resulting in glycerol and three liberated fatty acids. Pancreatic Lipase, however, only hydrolyzes two ester bonds from triglycerides.]] Lipase works with a substrate that consists usually of triglycerides. Triglycerides are composed of glycerol connected via ester bonds to three fatty acids. These molecules are split by hydrolysis (see figure). This is the reaction catalyzed by most lipases. Lipase acts on the exterior fatty acids of triglycerides, hydrolyzing the bonds and freeing the two outer fatty acids from the glycerol backbone. The <scene name='Sandbox_40/Active_site/1'>active site</scene> of lipase consists mainly of three residues. These three residues are SER152, ASP176, and HIS263. The mechanism for these hydrolysis reactions begins with SER152 attacking a carbonyl carbon, forming a tetrahedral intermediate. When the oxyanion reforms its double bonded form, the oxygen originally from the ester bond acts as the leaving group and accepts a hydrogen from HIS263. Next, water is converted into a nucleophile by donating a hydrogen to the HIS263, then attacking the new carbonyl. The SER152 now acts as the leaving group, producing a fatty acid chain which has been separated from glycerol and regenerating the enzyme active site. | ||
| + | =Evolutionary Conservation= | ||
| + | <scene name='Sandbox_40/Evolutionary_conservation/1'>TextToBeDisplayed</scene> | ||
Revision as of 03:21, 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. |
Horse Pancreatic Lipase
Introduction
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