Sandbox Reserved 1846: Difference between revisions
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=== Catalytic Triad === | === Catalytic Triad === | ||
[[Image:Final rayed image of binding pocket.png|400 px|right|thumb|Figure 1: Ser, His, Asp catalytic triad non-covalent stabilizing interactions with oxyanion hole.]] | [[Image:Final rayed image of binding pocket.png|400 px|right|thumb|Figure 1: Ser, His, Asp catalytic triad non-covalent stabilizing interactions with oxyanion hole.]] | ||
LCC catalyzes the breakdown of PET using a serine hydrolase mechanism with a <scene name='10/1075247/Catalytic_triad3_w_label/3'>catalytic triad</scene> of Ser165, His242, and Asp210. (Figure 1) | LCC catalyzes the breakdown of PET using a serine hydrolase mechanism with a <scene name='10/1075247/Catalytic_triad3_w_label/3'>catalytic triad</scene> of Ser165, His242, and Asp210. (Figure 1) Ser165 is deprotonated by His242 forming a reactive nucleophile (1). The oxygen of Ser165 attacks the carbonyl carbon of the substrate creating a tetrahedral intermediate (2). The tetrahedral intermediate collapses breaking the bond to the leaving group and forming an acyl-enzyme intermediate (3). Water is activated by His242 and its oxygen attacks the carbonyl carbon of the acyl-enzyme intermediate forming a second tetrahedral intermediate (4). The second tetrahedral intermediate collapses releasing the product and regenerating the enzyme. | ||
[[Image:FinalMechanism2.jpg|800 px|right|thumb|Figure 2: LCC mechanism. LCC hydrolyzes PET using a catalytic triad (Ser165, His242, Asp210) to cleave its ester bonds via two tetrahedral transition states to an acyl-enzyme intermediate.]] | [[Image:FinalMechanism2.jpg|800 px|right|thumb|Figure 2: LCC mechanism. LCC hydrolyzes PET using a catalytic triad (Ser165, His242, Asp210) to cleave its ester bonds via two tetrahedral transition states to an acyl-enzyme intermediate.]] | ||
