Sandbox 160: Difference between revisions

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== Structure & Function ==

The enzyme contains a NAD+ group which functions as a hydrogen acceptor during the course of the reaction which is bound to a Rossman fold. During the catalysis of glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate a hydride ion is enzymatically transferred from the aldehyde group of glyceraldehyde 3-phosphate to the nicotinamide ring of NAD+ reducing it to NADH (pink). The active site of GAPDH contains a cysteine (Cys149 colored green) residue which reacts with the glyceraldehyde 3-phosphate molecule through its -SH group. The substrate is covalently bound during the reaction through its aldehyde group to the -SH group and the reaction produces a thiohemiacetal. The <scene name='Sandbox_160/Newscene/1'>active site</scene> of the molecule is illustrated below.

The enzyme contains a NAD+ group which functions as a hydrogen acceptor during the course of the reaction which is bound to a Rossman fold. During the catalysis of glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate a hydride ion is enzymatically transferred from the aldehyde group of glyceraldehyde 3-phosphate to the nicotinamide ring of NAD+ reducing it to NADH (pink). The active site of GAPDH contains a cysteine (Cys149 colored green) residue which reacts with the glyceraldehyde 3-phosphate molecule through its -SH group. The substrate is covalently bound during the reaction through its aldehyde group to the -SH group of the cysteine residue and the resulting reaction produces a thiohemiacetal. Note that this reaction occurs through acid base catalysis with aid of a histidine residue (His176). The <scene name='Sandbox_160/Newscene/1'>active site</scene> of the molecule is illustrated below.

A simplified illustration of the net reaction is as follows:

D-glyceraldehyde 3-phosphate + phosphate + NAD+ ---------> 3-phospho-D-glyceroyl phosphate + NADH + H+

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 == Structure & Function ==
-The enzyme contains a NAD+ group which functions as a hydrogen acceptor during the course of the reaction which is bound to a Rossman fold. During the catalysis of glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate a hydride ion is enzymatically transferred from the aldehyde group of glyceraldehyde 3-phosphate to the nicotinamide ring of NAD+ reducing it to NADH (pink). The active site of GAPDH contains a cysteine (Cys149 colored green) residue which reacts with the glyceraldehyde 3-phosphate molecule through its -SH group. The substrate is covalently bound during the reaction through its aldehyde group to the -SH group and the reaction produces a thiohemiacetal. The <scene name='Sandbox_160/Newscene/1'>active site</scene> of the molecule is illustrated below.
+The enzyme contains a NAD+ group which functions as a hydrogen acceptor during the course of the reaction which is bound to a Rossman fold. During the catalysis of glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate a hydride ion is enzymatically transferred from the aldehyde group of glyceraldehyde 3-phosphate to the nicotinamide ring of NAD+ reducing it to NADH (pink). The active site of GAPDH contains a cysteine (Cys149 colored green) residue which reacts with the glyceraldehyde 3-phosphate molecule through its -SH group. The substrate is covalently bound during the reaction through its aldehyde group to the -SH group of the cysteine residue and the resulting reaction produces a thiohemiacetal. Note that this reaction occurs through acid base catalysis with aid of a histidine residue (His176). The <scene name='Sandbox_160/Newscene/1'>active site</scene> of the molecule is illustrated below.
+A simplified illustration of the net reaction is as follows:
+                               D-glyceraldehyde 3-phosphate + phosphate + NAD+ ---------> 3-phospho-D-glyceroyl phosphate + NADH + H+