Sandbox 160: Difference between revisions

From Proteopedia
Jump to navigationJump to search
No edit summary
No edit summary
Line 6: Line 6:
== Structure & Function ==  
== 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 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.   
The enzyme contains a functional 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)<ref name="reference 1">19243605 </ref>. 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 to the right.   


A simplified illustration of the net reaction is as follows:
A simplified illustration of the net reaction is as follows: