1anc
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1anc.jpg|left|200px]] | [[Image:1anc.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1anc", 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_1anc| PDB=1anc | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''ANIONIC TRYPSIN MUTANT WITH SER 214 REPLACED BY LYS''' | '''ANIONIC TRYPSIN MUTANT WITH SER 214 REPLACED BY LYS''' | ||
| Line 28: | Line 25: | ||
[[Category: Fletterick, R J.]] | [[Category: Fletterick, R J.]] | ||
[[Category: Mcgrath, M E.]] | [[Category: Mcgrath, M E.]] | ||
| - | [[Category: | + | [[Category: Anionic]] |
| - | [[Category: | + | [[Category: Hydrolase]] |
| - | [[Category: | + | [[Category: Serine protease]] |
| - | [[Category: | + | [[Category: Trypsin]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 10:28:37 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 07:28, 2 May 2008
ANIONIC TRYPSIN MUTANT WITH SER 214 REPLACED BY LYS
Overview
Much of the catalytic power of trypsin is derived from the unusual buried, charged side chain of Asp102. A polar cave provides the stabilization for maintaining the buried charge, and it features the conserved amino acid Ser214 adjacent to Asp102. Ser214 has been replaced with Ala, Glu, and Lys in rat anionic trypsin, and the consequences of these changes have been determined. Three-dimensional structures of the Glu and Lys variant trypsins reveal that the new 214 side chains are buried. The 2.2-A crystal structure (R = 0.150) of trypsin S214K shows that Lys214 occupies the position held by Ser214 and a buried water molecule in the buried polar cave. Lys214-N zeta is solvent inaccessible and is less than 5 A from the catalytic Asp102. The side chain of Glu214 (2.8 A, R = 0.168) in trypsin S214E shows two conformations. In the major one, the Glu carboxylate in S214E forms a hydrogen bond with Asp102. Analytical isoelectrofocusing results show that trypsin S214K has a significantly different isoelectric point than trypsin, corresponding to an additional positive charge. The kinetic parameter kcat demonstrates that, compared to trypsin, S214K has 1% of the catalytic activity on a tripeptide amide substrate and S214E is 44% as active. Electrostatic potential calculations provide corroboration of the charge on Lys214 and are consistent with the kinetic results, suggesting that the presence of Lys214 has disturbed the electrostatic potential of Asp102.
About this Structure
1ANC is a Single protein structure of sequence from Rattus rattus. Full crystallographic information is available from OCA.
Reference
Perturbing the polar environment of Asp102 in trypsin: consequences of replacing conserved Ser214., McGrath ME, Vasquez JR, Craik CS, Yang AS, Honig B, Fletterick RJ, Biochemistry. 1992 Mar 31;31(12):3059-64. PMID:1554694 Page seeded by OCA on Fri May 2 10:28:37 2008
