Document Detail


Intramolecular heme ligation of the cytochrome P450 2C9 R108H mutant demonstrates pronounced conformational flexibility of the B-C loop region: implications for substrate binding.
MedLine Citation:
PMID:  20815369     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
A previous study [Dickmann, L., et al. (2004) Mol. Pharmacol. 65, 842-850] revealed some unusual properties of the R108H mutant of cytochrome P450 2C9 (CYP2C9), including elevated thermostability relative to that of CYP2C9, as well as a UV-visible absorbance spectrum that was indicative of nitrogenous ligation to the heme iron. In our study, size-exclusion chromatography and UV-visible absorbance spectroscopy of CYP2C9 R108H monomers demonstrated that nitrogen ligation is indeed intramolecular. Pulsed electron paramagnetic resonance of CYP2C9 R108H monomers showed that a histidine is most likely bound to the heme as previously hypothesized. An energy-minimized model of the R108H mutant maintained a CYP fold, despite substantial movement of several loop regions of the mutant, and, therefore, represents an extreme example of a closed conformation of the enzyme. Molecular dynamics (MD) simulations of CYP2C9 were performed to study the range of energetically accessible CYP2C9 conformations. These in silico studies showed that the B-C loop region of CYP2C9 moves away from the heme to a position resembling the putative open conformation described for rabbit CYP2B4. A model involving the movement of the B-C loop region and R108 between the open and closed conformations of CYP2C9 is presented, which helps to explain the enzyme's ability to regio- and stereospecifically metabolize some ligands while allosterically activating others.
Authors:
Arthur G Roberts; Matthew J Cheesman; Andrew Primak; Michael K Bowman; William M Atkins; Allan E Rettie
Related Documents :
12598659 - Non-heme iron enzymes: contrasts to heme catalysis.
11278259 - Binding of co at the pro2 side is crucial for the activation of co-sensing transcriptio...
7880889 - Structural studies on recombinant and point mutants of flavocytochrome b2.
17660249 - Apo-nitrophorin 4 at atomic resolution.
19300529 - Effects of active site mutations in haemoglobin i from lucina pectinata: a molecular dy...
25283939 - Description of a new montane freshwater crab (crustacea: potamidae: geothelphusa) from ...
1525469 - Protein folding studied using hydrogen-exchange labeling and two-dimensional nmr.
20630859 - Isolation, cdna cloning, and structure-based functional characterization of oryctin, a ...
22277459 - Current status and future of anti-xa inhibitors.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2010-09-21
Journal Detail:
Title:  Biochemistry     Volume:  49     ISSN:  1520-4995     ISO Abbreviation:  Biochemistry     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-12-14     Completed Date:  2011-01-19     Revised Date:  2014-09-22    
Medline Journal Info:
Nlm Unique ID:  0370623     Medline TA:  Biochemistry     Country:  United States    
Other Details:
Languages:  eng     Pagination:  8700-8     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Aryl Hydrocarbon Hydroxylases / chemistry,  genetics*,  metabolism*
Chromatography, Gel
Electron Spin Resonance Spectroscopy
Escherichia coli / genetics
Heme / metabolism*
Histidine / metabolism
Humans
Molecular Dynamics Simulation
Mutant Proteins / chemistry,  genetics,  metabolism
Mutation
Protein Binding
Protein Conformation
Rabbits
Spectrophotometry, Ultraviolet
Substrate Specificity
Grant Support
ID/Acronym/Agency:
GM32165/GM/NIGMS NIH HHS; GM61904/GM/NIGMS NIH HHS; P01 GM032165/GM/NIGMS NIH HHS; R37 HL082900/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Mutant Proteins; 42VZT0U6YR/Heme; 4QD397987E/Histidine; EC 1.14.14.1/Aryl Hydrocarbon Hydroxylases; EC 1.14.14.1/CYP2C9 protein, human
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Efficient preparation of large-area graphene oxide sheets for transparent conductive films.
Next Document:  Lactone pathway to statins utilizing the Wittig reaction. The synthesis of rosuvastatin.