This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Huang, H.
Right arrow Articles by Hancock, R. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Huang, H.
Right arrow Articles by Hancock, R. E.

 Previous Article  |  Next Article 

J. Bacteriol., Jun 1996, 3085-3090, Vol 178, No. 11
Copyright © 1996, American Society for Microbiology

The role of specific surface loop regions in determining the function of the imipenem-specific pore protein OprD of Pseudomonas aeruginosa

H Huang and RE Hancock
Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.

Pseudomonas aeruginosa OprD is a specific porin which facilitates the uptake of basic amino acids and imipenem across the outer membrane. In this study, we examined the effects of deletions in six of the proposed eight surface loops of OprD on the in vivo and in vitro functions of this protein. Native OprD formed very small channels in planar lipid bilayers, with an average single-channel conductance in 1.0 M KCl of 20 pS. When large numbers of OprD channels were incorporated into lipid bilayer membranes, addition of increasing concentrations of imipenem to the bathing solutions resulted in a progressive blocking of the membrane conductance of KCl, indicating the presence of a specific binding site(s) for imipenem in the OprD channel. From these experiments, the concentration of imipenem value of resulting in 50% inhibition of the initial conductance was calculated as approximately 0.6 microM. In contrast, no decrease in channel conductance was observed for the OprDdeltaL2 channel upon addition of up to 2.4 microM imipenem, confirming that external loop 2 was involved in imipenem binding. Deletion of four to eight amino acids from loops 1 and 6 had no effect on antibiotic susceptibility, whereas deletion of eight amino acids from loops 5, 7, and 8 resulted in supersusceptibility to beta- lactams, quinolones, chloramphenicol, and tetracycline. Planar lipid bilayer analysis indicated that the OprDdeltaL5 channel had a 33-fold increase in single-channel conductance in 1 M KCl but had retained its imipenem binding site. The disposition of these loop regions in the interior of the OprD channel is discussed.


This article has been cited by other articles:

  • Danilchanka, O., Pavlenok, M., Niederweis, M. (2008). Role of Porins for Uptake of Antibiotics by Mycobacterium smegmatis. Antimicrob. Agents Chemother. 52: 3127-3134 [Abstract] [Full Text]  
  • Tamber, S., Maier, E., Benz, R., Hancock, R. E. W. (2007). Characterization of OpdH, a Pseudomonas aeruginosa Porin Involved in the Uptake of Tricarboxylates. J. Bacteriol. 189: 929-939 [Abstract] [Full Text]  
  • Siroy, A., Molle, V., Lemaitre-Guillier, C., Vallenet, D., Pestel-Caron, M., Cozzone, A. J., Jouenne, T., De, E. (2005). Channel Formation by CarO, the Carbapenem Resistance-Associated Outer Membrane Protein of Acinetobacter baumannii. Antimicrob. Agents Chemother. 49: 4876-4883 [Abstract] [Full Text]  
  • Jaouen, T., De, E., Chevalier, S., Orange, N. (2004). Pore Size Dependence on Growth Temperature Is a Common Characteristic of the Major Outer Membrane Protein OprF in Psychrotrophic and Mesophilic Pseudomonas Species. Appl. Environ. Microbiol. 70: 6665-6669 [Abstract] [Full Text]  
  • Kolayli, F., Karadenizli, A., Savli, H., Ergen, K., Hatirnaz, O., Balikci, E., Budak, F., Vahaboglu, H. (2004). Effect of carbapenems on the transcriptional expression of the oprD, oprM and oprN genes in Pseudomonas aeruginosa. J Med Microbiol 53: 915-920 [Abstract] [Full Text]  
  • Nikaido, H. (2003). Molecular Basis of Bacterial Outer Membrane Permeability Revisited. Microbiol. Mol. Biol. Rev. 67: 593-656 [Abstract] [Full Text]  
  • Epp, S. F., Köhler, T., Plésiat, P., Michéa-Hamzehpour, M., Frey, J., Pechère, J.-C. (2001). C-Terminal Region of Pseudomonas aeruginosa Outer Membrane Porin OprD Modulates Susceptibility to Meropenem. Antimicrob. Agents Chemother. 45: 1780-1787 [Abstract] [Full Text]  
  • Ochs, M. M., Bains, M., Hancock, R. E. W. (2000). Role of Putative Loops 2 and 3 in Imipenem Passage through the Specific Porin OprD of Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 44: 1983-1985 [Abstract] [Full Text]  
  • Bina, J., Bains, M., Hancock, R. E. W. (2000). Functional Expression in Escherichia coli and Membrane Topology of Porin HopE, a Member of a Large Family of Conserved Proteins in Helicobacter pylori. J. Bacteriol. 182: 2370-2375 [Abstract] [Full Text]  
  • Bina, J. E., Alm, R. A., Uria-Nickelsen, M., Thomas, S. R., Trust, T. J., Hancock, R. E. W. (2000). Helicobacter pylori Uptake and Efflux: Basis for Intrinsic Susceptibility to Antibiotics In Vitro. Antimicrob. Agents Chemother. 44: 248-254 [Abstract] [Full Text]  
  • Gottfredsson, M., Erlendsdóttir, H., Sigfússon, A., Gudmundsson, S. (1998). Characteristics and Dynamics of Bacterial Populations during Postantibiotic Effect Determined by Flow Cytometry. Antimicrob. Agents Chemother. 42: 1005-1011 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»