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.


1luv

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1luv.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1luv.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1luv| PDB=1luv | SCENE= }}
{{STRUCTURE_1luv| PDB=1luv | SCENE= }}
-
'''CATALYTIC AND STRUCTURAL EFFECTS OF AMINO-ACID SUBSTITUTION AT HIS 30 IN HUMAN MANGANESE SUPEROXIDE DISMUTASE: INSERTION OF VAL CGAMMA INTO THE SUBSTRATE ACCESS CHANNEL'''
+
===CATALYTIC AND STRUCTURAL EFFECTS OF AMINO-ACID SUBSTITUTION AT HIS 30 IN HUMAN MANGANESE SUPEROXIDE DISMUTASE: INSERTION OF VAL CGAMMA INTO THE SUBSTRATE ACCESS CHANNEL===
-
==Overview==
+
<!--
-
Catalysis of the disproportionation of superoxide by human manganese superoxide dismutase (MnSOD) is characterized by an initial burst of catalysis followed by a much slower region that is zero order in superoxide and due to a product inhibition by peroxide anion. We have prepared site-specific mutants with replacements at His30, the side chain of which lies along the substrate access channel and is about 5.8 A from the metal. Using pulse radiolysis to generate superoxide, we have determined that kcat/K(m) was decreased and product inhibition increased for H30V MnSOD, both by 1-2 orders of magnitude, compared with wild type, H30N, and H30Q MnSOD. These effects are not attributed to the redox potentials, which are similar for all of these variants. An investigation of the crystal structure of H30V Mn(III)SOD compared with wild type, H30Q, and H30N Mn(III)SOD showed the positions of two gamma carbons of Val30 in the active site; Cgamma1 overlaps Cgamma of His30 in wild type, and Cgamma2 extends into the substrate access channel and occupies the approximate position of a water molecule in the wild type. The data suggest that Cgamma2 of the Val side chain has significantly interrupted catalysis by this overlap into the access channel with possible overlap with the substrate-product binding site. This is supported by comparison of the crystal structure of H30V MnSOD with that of azide bound to Mn(III)SOD from Thermus thermophilus and by visible absorption spectra showing that azide binding to the metal in H30V Mn(III)SOD is abolished. Moreover, the presence of Val30 caused a 100-fold decrease in the rate constant for dissociation of the product-inhibited complex compared with wild type.
+
The line below this paragraph, {{ABSTRACT_PUBMED_12627943}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 12627943 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_12627943}}
==About this Structure==
==About this Structure==
Line 35: Line 39:
[[Category: Mnsod]]
[[Category: Mnsod]]
[[Category: Wild type]]
[[Category: Wild type]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:18:50 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jul 2 22:21:20 2008''

Revision as of 19:21, 2 July 2008

Image:1luv.png

Template:STRUCTURE 1luv

CATALYTIC AND STRUCTURAL EFFECTS OF AMINO-ACID SUBSTITUTION AT HIS 30 IN HUMAN MANGANESE SUPEROXIDE DISMUTASE: INSERTION OF VAL CGAMMA INTO THE SUBSTRATE ACCESS CHANNEL

Template:ABSTRACT PUBMED 12627943

About this Structure

1LUV is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Catalytic and structural effects of amino acid substitution at histidine 30 in human manganese superoxide dismutase: insertion of valine C gamma into the substrate access channel., Hearn AS, Stroupe ME, Cabelli DE, Ramilo CA, Luba JP, Tainer JA, Nick HS, Silverman DN, Biochemistry. 2003 Mar 18;42(10):2781-9. PMID:12627943

Page seeded by OCA on Wed Jul 2 22:21:20 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

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