1ab9
From Proteopedia
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| - | [[Image:1ab9.gif|left|200px]] | + | [[Image:1ab9.gif|left|200px]] |
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| - | '''CRYSTAL STRUCTURE OF BOVINE GAMMA-CHYMOTRYPSIN''' | + | {{Structure |
| + | |PDB= 1ab9 |SIZE=350|CAPTION= <scene name='initialview01'>1ab9</scene>, resolution 1.60Å | ||
| + | |SITE= <scene name='pdbsite=CAT:Catalytic+Triad'>CAT</scene> | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Chymotrypsin Chymotrypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.1 3.4.21.1] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''CRYSTAL STRUCTURE OF BOVINE GAMMA-CHYMOTRYPSIN''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1AB9 is a [ | + | 1AB9 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AB9 OCA]. |
==Reference== | ==Reference== | ||
| - | X-ray crystal structure of a dipeptide-chymotrypsin complex in an inhibitory interaction., Kashima A, Inoue Y, Sugio S, Maeda I, Nose T, Shimohigashi Y, Eur J Biochem. 1998 Jul 1;255(1):12-23. PMID:[http:// | + | X-ray crystal structure of a dipeptide-chymotrypsin complex in an inhibitory interaction., Kashima A, Inoue Y, Sugio S, Maeda I, Nose T, Shimohigashi Y, Eur J Biochem. 1998 Jul 1;255(1):12-23. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9692896 9692896] |
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Chymotrypsin]] | [[Category: Chymotrypsin]] | ||
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[[Category: digestion]] | [[Category: digestion]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | [[Category: | + | [[Category: pancrea]] |
[[Category: serine protease]] | [[Category: serine protease]] | ||
[[Category: zymogen]] | [[Category: zymogen]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 09:55:24 2008'' |
Revision as of 07:55, 20 March 2008
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| , resolution 1.60Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Activity: | Chymotrypsin, with EC number 3.4.21.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF BOVINE GAMMA-CHYMOTRYPSIN
Overview
The dipeptide D-leucyl-L-phenylalanyl p-fluorobenzylamide (D-Leu-Phe-NH-BzlF) inhibits chymotrypsin strongly in a competitive manner with the Ki value of 0.61 microM [Shimohigashi, Y., Maeda, I., Nose, T., Ikesue, K., Sakamoto, H., Ogawa, T., Ide, Y., Kawahara, M., Nezu, T., Terada, Y., Kawano, K. & Ohno, M. (1996) J. Chem. Soc. Perkin Trans. 1, 2479-2485]. The structure/activity studies have suggested a unique inhibitory conformation, in which the C-terminal benzyl group fits the chymotrypsin S1 site and the hydrophobic core constructed by the side chains of D-Leu-Phe fits the S2 or S1' site. To verify this assumption, the molecular structure of the complex between the dipeptide and gamma-chymotrypsin has been determined crystallographically. Gamma-chymotrypsin itself was first crystallized and refined at 1.6-A resolution. The refined structure was virtually identical to the conformation reported and the electron density at the active site was interpreted as a pentapeptide Thr-Pro-Gly-Val-Tyr derived from autolysis of the enzyme (residues 224-228). The chymotrypsin-dipeptide complex was obtained by soaking the crystals of gamma-chymotrypsin in a solution saturated with the dipeptide inhibitor. The crystal structure of the complex has been refined at 1.8-A resolution to a crystallographic R-factor of 18.1%. The structure of gamma-chymotrypsin in the complex agreed fairly well with that of gamma-chymotrypsin per se with a rmsd of 0.13 A for all the C alpha carbons. Two inhibitor molecules were assigned in an asymmetric unit, i.e. one in the active site and the other at the interface of two symmetry-related enzyme molecules. In both sites dipeptides adopted very similar folded conformations, in which side chains of D-Leu-Phe are spatially proximal. In the active site where the binding of dipeptide was judged to be a direct cause of inhibition, C-terminal p-fluorobenzylamide group of the dipeptide, NH-BzlF, was found in the S1 hydrophobic pocket. At the bottom of this pocket, the p-fluorine atom hydrogen bonded with a water molecule, probably to enhance the inhibitory activity. The stereospecific interaction of R and S isomers of the dipeptide with C-terminal NH-C*H(CH3)-C6H5 was well explained by the space available for methyl replacement in the complex. The hydrophobic core constructed by side chains of D-Leu-Phe was found at the broad S2 site. Interestingly, a novel interaction was found between the inhibitor Phe residue and chymotrypsin His57, the phenyl of Phe and the imidazole of His being in a pi-pi stacking interaction at a distance 3.75 A.
About this Structure
1AB9 is a Protein complex structure of sequences from Bos taurus. Full crystallographic information is available from OCA.
Reference
X-ray crystal structure of a dipeptide-chymotrypsin complex in an inhibitory interaction., Kashima A, Inoue Y, Sugio S, Maeda I, Nose T, Shimohigashi Y, Eur J Biochem. 1998 Jul 1;255(1):12-23. PMID:9692896
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