microbiology, Vol 143, 1029-1035, Copyright © 1997 by Society for General Microbiology

ARTICLES

Growth temperature dependence of channel size of the major outer- membrane protein (OprF) in psychrotrophic Pseudomonas fluorescens strains

E De, N Orange, N Saint, J Guerillon, R De Mot and G Molle
Institut Federatif de Recherche, Multidisciplinaire sur les Peptides, URA 500 CNRS, Faculte des Sciences, Mont-Saint-Aignan, France.

The outer-membrane (OM) permeability of the psychrotrophic bacterium Pseudomonas fluorescens strain MF0 for the beta-lactam mezlocillin is increased at the optimum growth temperature (28 degrees C) compared to low growth temperatures (8 degrees C). In an attempt to explain this phenomenon, OM protein content was studied in cultures grown at both temperatures. No significant difference in proportion or composition was found, suggesting that a change in the structure and function of porins could be responsible for the differential permeability. The major OM protein OprF of two psychrotrophic P. fluorescens strains, MF0 and OE 28.3, was purified from cultures grown at 8 degrees C and 28 degrees C in order to reincorporate them in solvent-free lipid bilayers. From cultures grown at the same temperature, OprF displayed very similar channel-forming properties for both strains. Decreasing the growth temperature induced a threefold reduction of the major conductance values (250-270 pS in 1 M NaCl for 28 degrees C cultures and 80-90 pS in 1 M NaCl for 8 degrees C cultures). The trypsin digestion kinetics showed a very different reactivity for these porins between cultures grown at 8 degrees C and 28 degrees C. This may indicate that the pore structure of OprF is modified depending on the growth temperature, as suggested by its functional behaviour.

This article has been cited by other articles:

				E. Zakharian and R. N. Reusch Pore Characteristics of Nontypeable Haemophilus influenzae Outer Membrane Protein P5 in Planar Lipid Bilayers Biophys. J., November 1, 2006; 91(9): 3242 - 3248. [Abstract] [Full Text] [PDF]

				E. Sugawara, E. M. Nestorovich, S. M. Bezrukov, and H. Nikaido Pseudomonas aeruginosa Porin OprF Exists in Two Different Conformations J. Biol. Chem., June 16, 2006; 281(24): 16220 - 16229. [Abstract] [Full Text] [PDF]

				J. Bodilis and S. Barray Molecular evolution of the major outer-membrane protein gene (oprF) of Pseudomonas. Microbiology, April 1, 2006; 152(Pt 4): 1075 - 1088. [Abstract] [Full Text] [PDF]

				T. Jaouen, E. De, S. Chevalier, and N. Orange Pore Size Dependence on Growth Temperature Is a Common Characteristic of the Major Outer Membrane Protein OprF in Psychrotrophic and Mesophilic Pseudomonas Species Appl. Envir. Microbiol., November 1, 2004; 70(11): 6665 - 6669. [Abstract] [Full Text] [PDF]

				H. Nikaido Molecular Basis of Bacterial Outer Membrane Permeability Revisited Microbiol. Mol. Biol. Rev., December 1, 2003; 67(4): 593 - 656. [Abstract] [Full Text] [PDF]

				A. Arora, D. Rinehart, G. Szabo, and L. K. Tamm Refolded Outer Membrane Protein A of Escherichia coli Forms Ion Channels with Two Conductance States in Planar Lipid Bilayers J. Biol. Chem., January 21, 2000; 275(3): 1594 - 1600. [Abstract] [Full Text] [PDF]