This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
Sandbox Reserved 1442
From Proteopedia
(Difference between revisions)
| Line 4: | Line 4: | ||
<StructureSection load='1nu6' size='340' side='right' caption='Dipeptidyl Peptidase IV' scene=''> | <StructureSection load='1nu6' size='340' side='right' caption='Dipeptidyl Peptidase IV' scene=''> | ||
| - | |||
The DPP-IV active site exists at the intersection of a α/β hydrolase domain and a β-propeller domain and consists of the catalytic triad and supporting residues. The catalytic triad is made up of a nucleophile, Serine630, a base, Histidine740, and an acid, Aspartate708. Also essential to the cleaving mechanism are two supporting residues, Tyr547 and Tyr631, that stabilize the oxyanion tetrahedral intermediate by forming hydrogen bonds with the oxyanion. In addition, there are anchoring residues that coordinate the carbonyl of the N-terminal amino acid residue of the substrate and align it for the nucleophilic attack by Ser630. These residues are Glu205, Glu206, Asn710, and Arg125. | The DPP-IV active site exists at the intersection of a α/β hydrolase domain and a β-propeller domain and consists of the catalytic triad and supporting residues. The catalytic triad is made up of a nucleophile, Serine630, a base, Histidine740, and an acid, Aspartate708. Also essential to the cleaving mechanism are two supporting residues, Tyr547 and Tyr631, that stabilize the oxyanion tetrahedral intermediate by forming hydrogen bonds with the oxyanion. In addition, there are anchoring residues that coordinate the carbonyl of the N-terminal amino acid residue of the substrate and align it for the nucleophilic attack by Ser630. These residues are Glu205, Glu206, Asn710, and Arg125. | ||
| + | |||
| + | "Creating of Nucleophile" | ||
| + | The hydrogen bond between the carboxyl group of aspartate, which is deprotonated at physiological pH, and histidine increases the pKa of the imidazole nitrogen of histidine from 7 to 12, thus increasing its basicity. It also aligns histidine within the active site by restricting rotation of its side chain. | ||
Revision as of 16:53, 30 January 2018
Dipeptidyl Peptidase IV (DPP-IV)
Active Site of Dipeptidyl Peptidase IV (DPP-IV)
| |||||||||||
