Sandbox 49: Difference between revisions

Line 11:

Important for the tertiary structure of the protein, are several different factors that function to hold each of the domains together in the proper orientation, the <scene name='Sandbox_49/Lipase_hydrohpobic_residues/1'>hydrophobic residues</scene> certainly make a difference as one might expect, since all proteins generally fold to shield these from interaction with water, the cysteine residues that Lipase has also play a major role since they form <scene name='Sandbox_49/Disulfide_bonds/1'>Disulfide Bonds</scene>, Lipase has 12 disulfide bonds in all.

Lipase ~~also has~~ a ~~<scene name='Sandbox_49/Ca_ligands/1'>Ca Ligand</scene> that noncovalently binds to~~ residues: ~~Glu 187, Arg 190~~, Asp ~~192~~, ~~Asp 195~~. ~~There is one Calcium ion bound per chain in~~ the ~~enzyme~~.

Lipase Active Sites

The ~~<scene name='Sandbox_49/Lipase_active_sites_test/1'>Lipase Active Sites</scene>~~ catalytic ~~groups are protected~~ by a ~~flap~~ that ~~folds over~~ the ~~are~~ when a substrate is ~~bound~~, ~~aiding~~ in the ~~catalytic function~~ of the ~~enzyme~~.

The Lipase Active Sites consists of a catalytic triad of residues: Ser 152, Asp 176, and His 263. Residues Phe 77 and Leu 153 are also important for the mechanism of Lipase. The catalytic triad is covered by a “lid” that protects the active site of the enyzyme, and prevents the binding of substrate when it is closed and covering the active site. In total lipase has 2 active sites, 1 for each of the domains that make up the enzyme.

Mechanism

The mechanism of action for pancreatic lipase can be broken down into 4 main steps. In the first step His 263 deprotonates Ser 152 that in turn attacks the carboxy carbon of triacylglyceride substrate, it is a nucleophilic addition reaction. In the second step of the reaction the oxyanion hole collapses resulting in the elimination of the diacylglycerol product, that deprotonates His 263 and acylates Ser 152 as a result. In the third step His 263 deprotonates water, which in turn attacks the carboxyl carbon of the acylated Ser 152 in another nucleophilic addition reaction. And in the last step the oxyanion hole collapses again resulting in the elimination of the carboxylate product and Ser 152 which then deprotonates His 263.

Sandbox 49: Difference between revisions

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@@ Line 11: / Line 11: @@
 Important for the tertiary structure of the protein, are several different factors that function to hold each of the domains together in the proper orientation, the <scene name='Sandbox_49/Lipase_hydrohpobic_residues/1'>hydrophobic residues</scene> certainly make a difference as one might expect, since all proteins generally fold to shield these from interaction with water, the cysteine residues that Lipase has also play a major role since they form <scene name='Sandbox_49/Disulfide_bonds/1'>Disulfide Bonds</scene>, Lipase has 12 disulfide bonds in all.
-Lipase also has a <scene name='Sandbox_49/Ca_ligands/1'>Ca Ligand</scene> that noncovalently binds to residues: Glu 187, Arg 190, Asp 192, Asp 195. There is one Calcium ion bound per chain in the enzyme.
+Lipase Active Sites
-The <scene name='Sandbox_49/Lipase_active_sites_test/1'>Lipase Active Sites</scene> catalytic groups are protected by a flap that folds over the are when a substrate is bound, aiding in the catalytic function of the enzyme.
+The Lipase Active Sites consists of a catalytic triad of residues: Ser 152, Asp 176, and His 263. Residues Phe 77 and Leu 153 are also important for the mechanism of Lipase. The catalytic triad is covered by a “lid” that protects the active site of the enyzyme, and prevents the binding of substrate when it is closed and covering the active site. In total lipase has 2 active sites, 1 for each of the domains that make up the enzyme.
+Mechanism
+	The mechanism of action for pancreatic lipase can be broken down into 4 main steps. In the first step His 263 deprotonates Ser 152 that in turn attacks the carboxy carbon of triacylglyceride substrate, it is a nucleophilic addition reaction. In the second step of the reaction the oxyanion hole collapses resulting in the elimination of the diacylglycerol product, that deprotonates His 263 and acylates Ser 152 as a result. In the third step His 263 deprotonates water, which in turn attacks the carboxyl carbon of the acylated Ser 152 in another nucleophilic addition reaction. And in the last step the oxyanion hole collapses again resulting in the elimination of the carboxylate product and Ser 152 which then deprotonates His 263.