We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.

1q5p

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1q5p.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1q5p.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1q5p| PDB=1q5p | SCENE= }}
{{STRUCTURE_1q5p| PDB=1q5p | SCENE= }}
-
'''S156E/S166D variant of Bacillus lentus subtilisin'''
+
===S156E/S166D variant of Bacillus lentus subtilisin===
-
==Overview==
+
<!--
-
The properties of the transition state for serine protease-catalyzed hydrolysis of an amide bond were determined for a series of subtilisin variants from Bacillus lentus. There is no significant change in the structure of the enzyme upon introduction of charged mutations S156E/S166D, suggesting that changes in catalytic activity reflect global properties of the enzyme. The effect of charged mutations on the pK(a) of the active site histidine-64 N(epsilon)(2)-H was correlated with changes in the second-order rate constant k(cat)/K(m) for hydrolysis of tetrapeptide anilides at low ionic strength with a Bronsted slope alpha = 1.1. The solvent isotope effect (D)2(O)(k(cat)/K(m))(1) = 1.4 +/- 0.2. These results are consistent with a rate-limiting breakdown of the tetrahedral intermediate in the acylation step with hydrogen bond stabilization of the departing amine leaving group. There is an increase in the ratio of hydrolysis of succinyl-Ala-Ala-Pro-Phe-anilides for p-nitroaniline versus aniline leaving groups with variants with more basic active site histidines that can be described by the interaction coefficient p(xy) = delta beta(lg)/delta pK(a) (H64) = 0.15. This is attributed to increased hydrogen bonding of the active site imidazolium N-H to the more basic amine leaving group as well as electrostatic destabilization of the transition state. A qualitative characterization of the transition state is presented in terms of a reaction coordinate diagram that is defined by the structure-reactivity parameters.
+
The line below this paragraph, {{ABSTRACT_PUBMED_12962477}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 12962477 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_12962477}}
==About this Structure==
==About this Structure==
Line 34: Line 38:
[[Category: Site-specific variant]]
[[Category: Site-specific variant]]
[[Category: Subtilisin]]
[[Category: Subtilisin]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:53:41 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 09:41:46 2008''

Revision as of 06:41, 28 July 2008

Image:1q5p.png

Template:STRUCTURE 1q5p

S156E/S166D variant of Bacillus lentus subtilisin

Template:ABSTRACT PUBMED 12962477

About this Structure

1Q5P is a Single protein structure of sequence from Bacillus lentus. Full crystallographic information is available from OCA.

Reference

Do enzymes change the nature of transition states? Mapping the transition state for general acid-base catalysis of a serine protease., Bott RR, Chan G, Domingo B, Ganshaw G, Hsia CY, Knapp M, Murray CJ, Biochemistry. 2003 Sep 16;42(36):10545-53. PMID:12962477

Page seeded by OCA on Mon Jul 28 09:41:46 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1q5p"
Personal tools