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.
1pjp
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1pjp.gif|left|200px]] | [[Image:1pjp.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1pjp", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_1pjp| PDB=1pjp | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''THE 2.2 A CRYSTAL STRUCTURE OF HUMAN CHYMASE IN COMPLEX WITH SUCCINYL-ALA-ALA-PRO-PHE-CHLOROMETHYLKETONE''' | '''THE 2.2 A CRYSTAL STRUCTURE OF HUMAN CHYMASE IN COMPLEX WITH SUCCINYL-ALA-ALA-PRO-PHE-CHLOROMETHYLKETONE''' | ||
| Line 33: | Line 30: | ||
[[Category: Strobl, S.]] | [[Category: Strobl, S.]] | ||
[[Category: Wang, Z M.]] | [[Category: Wang, Z M.]] | ||
| - | [[Category: | + | [[Category: Angiotensin]] |
| - | [[Category: | + | [[Category: Dipeptidyl carboxypeptidase]] |
| - | [[Category: | + | [[Category: Human chymase]] |
| - | [[Category: | + | [[Category: Serine proteinase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:09:47 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 02:09, 3 May 2008
THE 2.2 A CRYSTAL STRUCTURE OF HUMAN CHYMASE IN COMPLEX WITH SUCCINYL-ALA-ALA-PRO-PHE-CHLOROMETHYLKETONE
Overview
Human chymase (HC) is a chymotrypsin-like serine proteinase expressed by mast cells. The 2.2 A crystal structure of HC complexed to the peptidyl inhibitor, succinyl-Ala-Ala-Pro-Phe-chloromethylketone (CMK), was solved and refined to a crystallographic R-factor of 18.4 %. The HC structure exhibits the typical folding pattern of a chymotrypsin-like serine proteinase, and shows particularly similarity to rat chymase 2 (rat mast cell proteinase II) and human cathepsin G. The peptidyl-CMK inhibitor is covalently bound to the active-site residues Ser195 and His57; the peptidyl moiety juxtaposes the S1 entrance frame segment 214-217 by forming a short antiparallel beta-sheet. HC is a highly efficient angiotensin-converting enzyme. Modeling of the chymase-angiotensin I interaction guided by the geometry of the bound chloromethylketone inhibitor indicates that the extended substrate binding site contains features that may generate the dipeptidyl carboxypeptidase-like activity needed for efficient cleavage and activation of the hormone. The C-terminal carboxylate group of angiotensin I docked into the active-site cleft, with the last two residues extending beyond the active site, is perfectly localized to make a favorable hydrogen bond and salt bridge with the amide nitrogen of the Lys40-Phe41 peptide bond and with the epsilon-ammonium group of the Lys40 side-chain. This amide positioning is unique to the chymase-related proteinases, and only chymases from primates possess a Lys residue at position 40. Thus, the structure conveniently explains the preferred conversion of angiotensin I to angiotensin II by human chymase.
About this Structure
1PJP is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The 2.2 A crystal structure of human chymase in complex with succinyl-Ala-Ala-Pro-Phe-chloromethylketone: structural explanation for its dipeptidyl carboxypeptidase specificity., Pereira PJ, Wang ZM, Rubin H, Huber R, Bode W, Schechter NM, Strobl S, J Mol Biol. 1999 Feb 12;286(1):163-73. PMID:9931257 Page seeded by OCA on Sat May 3 05:09:47 2008
