Document Detail


Electrostatic properties of the anion selective porin Omp32 from Delftia acidovorans and of the arginine cluster of bacterial porins.
MedLine Citation:
PMID:  12021430     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The functional properties of the anion-selective porin Omp32 from the bacterium Delftia acidovorans, formerly Comamonas acidovorans, are determined by the particularly narrow channel constriction and the electrostatic field inside and outside the pore. A cluster of arginines (Arg 38, Arg 75, and Arg 133) determines the electrostatic field close to the constriction zone. Stacked amino acids carrying charges are prone to drastic pK(a) shifts. However, optimized calculations of the titration behavior of charged groups, based on the finite-difference Poisson-Boltzmann technique, suggest that all the arginines are charged at physiological pH. Protonation of the clustered arginines is stabilized by one buried glutamate residue (Glu 58), which is strongly interacting with Arg 75 and Arg 38. This functional arrangement of three charged amino acid residues is of general significance because it is found in the constriction zones of all known 16-stranded porins from the alpha-, beta-, and gamma-proteobacteria.
Authors:
Ulrich Zachariae; Assen Koumanov; Harald Engelhardt; Andrey Karshikoff
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Protein science : a publication of the Protein Society     Volume:  11     ISSN:  0961-8368     ISO Abbreviation:  Protein Sci.     Publication Date:  2002 Jun 
Date Detail:
Created Date:  2002-05-21     Completed Date:  2003-07-29     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  9211750     Medline TA:  Protein Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1309-19     Citation Subset:  IM    
Affiliation:
Abteilung Molekulare Strukturbiologie, Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany.
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Arginine / chemistry*
Bacterial Proteins*
Delftia acidovorans / chemistry*
Hydrogen-Ion Concentration
Models, Molecular
Molecular Sequence Data
Porins / chemistry*
Protein Structure, Tertiary
Proteobacteria / chemistry
Sequence Alignment
Static Electricity
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 0/Omp32 protein, bacteria; 0/Porins; 74-79-3/Arginine
Comments/Corrections

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