1pq7
|
Trypsin at 0.8 A, pH5 / borax
OverviewOverview
A series of crystal structures of trypsin, containing either an, autoproteolytic cleaved peptide fragment or a covalently bound inhibitor, were determined at atomic and ultra-high resolution and subjected to ab, initio quantum chemical calculations and multipole refinement. Quantum, chemical calculations reproduced the observed active site crystal, structure with severe deviations from standard stereochemistry and, indicated the protonation state of the catalytic residues. Multipole, refinement directly revealed the charge distribution in the active site, and proved the validity of the ab initio calculations. The combined, results confirmed the catalytic function of the active site residues and, the two water molecules acting as the nucleophile and the proton donor., The crystal structures represent snapshots from the reaction pathway, close to a tetrahedral intermediate. The de-acylation of trypsin then, occurs in true SN2 fashion.
About this StructureAbout this Structure
1PQ7 is a Single protein structure of sequence from Fusarium oxysporum with SO4 and ARG as ligands. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.
ReferenceReference
Trypsin revisited: crystallography AT (SUB) atomic resolution and quantum chemistry revealing details of catalysis., Schmidt A, Jelsch C, Ostergaard P, Rypniewski W, Lamzin VS, J Biol Chem. 2003 Oct 31;278(44):43357-62. Epub 2003 Aug 22. PMID:12937176
Page seeded by OCA on Wed Nov 21 00:01:11 2007