Protein Science, Vol 7, Issue 7 1603-1611, Copyright © 1998 by Cold Spring Harbor Laboratory Press

ARTICLE

Porin mutants with new channel properties

B. SCHMID, L. MAVEYRAUD, M. KROMER and G. E. SCHULZ
Institut fur Organische Chemie und Biochemie, Albert-Ludwigs-Universitat, Freiburg im Breisgau, Germany

The general diffusion porin from Rhodopseudomonas blastica was produced in large amounts in Escherichia coli inclusion bodies and (re)natured to the exact native structure. Here, we report on 13 mutants at the pore eyelet giving rise to new diffusion properties as measured in planar lipid bilayer experiments. The crystal structures of seven of these mutants were established. The effects of charge-modifying mutations at the pore eyelet are consistent with the known selectivity for cations. Deletions of 16 and 27 residues of the constriction loop L3 resulted in labile trimers and pores. The reduction of the eyelet cross section by introducing tryptophans gave rise to a closely correlated decrease of the conductivities. A mutant with six newly introduced tryptophans in the eyelet closed its pore in a defined manner within seconds under a voltage of 20 mV, suggesting the existence of two states. The results indicate that the pore can be engineered in a rational manner.
CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Olesky, S. Zhao, R. L. Rosenberg, and R. A. Nicholas Porin-Mediated Antibiotic Resistance in Neisseria gonorrhoeae: Ion, Solute, and Antibiotic Permeation through PIB Proteins with penB Mutations. J. Bacteriol., April 1, 2006; 188(7): 2300 - 2308. [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]

				S. Bransburg-Zabary, E. Nachliel, and M. Gutman A Fast in Silico Simulation of Ion Flux through the Large-Pore Channel Proteins Biophys. J., December 1, 2002; 83(6): 3001 - 3011. [Abstract] [Full Text] [PDF]

				M. Bannwarth and G. E. Schulz Asymmetric conductivity of engineered porins Protein Eng. Des. Sel., October 1, 2002; 15(10): 799 - 804. [Abstract] [Full Text] [PDF]

				H. Kleivdal, P. Puntervoll, and H. B. Jensen Topological investigations of the FomA porin from Fusobacterium nucleatum and identification of the constriction loop L6 Microbiology, April 1, 2001; 147(4): 1059 - 1067. [Abstract] [Full Text]

				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]

				J. L. Shannon and R. C. Fernandez The C-Terminal Domain of the Bordetella pertussis Autotransporter BrkA Forms a Pore in Lipid Bilayer Membranes J. Bacteriol., September 15, 1999; 181(18): 5838 - 5842. [Abstract] [Full Text]