Sandbox Reserved 1846: Difference between revisions
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=== Catalytic Triad === | === Catalytic Triad === | ||
LCC catalyzes the breakdown of PET using a serine hydrolase mechanism with a | 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. (1) The reaction begins when His242 deprotonates Ser165, which activates it as a nucleophile. (2) Ser165 then attacks the carbonyl carbon of an ester bond in the PET polymer to form a tetrahedral intermediate. (3) This tetrahedral intermediate is stabilized by an oxyanion hole formed by the backbone amides of Met166 and Tyr95. (4) The intermediate collapses; one product is released and an acyl-enzyme intermediate is formed. (5) A water molecule, activated by His242, then attacks the acyl-enzyme. This releases the second product and resets the enzyme’s active site. | ||
[[Image:Mech2.png|800 px|right|thumb|Figure 1: LCC mechanism. LCC hydrolyzes PET using a catalytic triad (Ser165, His242, Asp210) to cleave ester bonds via a tetrahedral intermediate.]] | [[Image:Mech2.png|800 px|right|thumb|Figure 1: LCC mechanism. LCC hydrolyzes PET using a catalytic triad (Ser165, His242, Asp210) to cleave ester bonds via a tetrahedral intermediate.]] | ||
