Gram-negative bacterial cells are surrounded by a double layer of membranes, i.e., the outer membrane and the inner, cytoplasmic membrane. The outer membrane is in many ways an ideal biological membrane for study, because its composition as well as functions are quite simple. The major advances in this field has been the discovery of porins, membrane proteins forming nonspecific channels for the diffusion of any small, hydrophilic solutes, as well as at least one membrane protein shown to form a configurationally specific channel. The major objectives of this project is to understand the structure-function relationship in this simple membrane, as well as mechanisms of its assembly. Special emphasis will be placed on the following areas. (1) Structure of porin and the properties of the channel. These are important because practically all antibiotics and chemotherapeutic agents must diffuse through these channels before they reach their targets, and the properties of the channel are major factors that affect the barrier properties of the outer membrane. (2) Structure-function relationship in specific channels, as a model for the central unit in any specific membrane transport systems. (3) Permeability of the non-protein regions of the outer membrane. This is again an important factor in determining the barrier properties of the membrane. (4) Selected aspects of the membrane biogenesis, including the cell cycle dependence of the synthesis or insertion of certain proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI009644-16
Application #
3124590
Study Section
Cognition and Perception Study Section (CP)
Project Start
1976-03-01
Project End
1986-02-28
Budget Start
1985-03-01
Budget End
1986-02-28
Support Year
16
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Type
Schools of Arts and Sciences
DUNS #
094878337
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Nikaido, Hiroshi (2018) RND transporters in the living world. Res Microbiol 169:363-371
Sugawara, Etsuko; Kojima, Seiji; Nikaido, Hiroshi (2016) Klebsiella pneumoniae Major Porins OmpK35 and OmpK36 Allow More Efficient Diffusion of ?-Lactams than Their Escherichia coli Homologs OmpF and OmpC. J Bacteriol 198:3200-3208
Kinana, Alfred D; Vargiu, Attilio V; May, Thithiwat et al. (2016) Aminoacyl ?-naphthylamides as substrates and modulators of AcrB multidrug efflux pump. Proc Natl Acad Sci U S A 113:1405-10
Kinana, Alfred D; Vargiu, Attilio V; Nikaido, Hiroshi (2016) Effect of site-directed mutations in multidrug efflux pump AcrB examined by quantitative efflux assays. Biochem Biophys Res Commun 480:552-557
Soparkar, Ketaki; Kinana, Alfred D; Weeks, Jon W et al. (2015) Reversal of the Drug Binding Pocket Defects of the AcrB Multidrug Efflux Pump Protein of Escherichia coli. J Bacteriol 197:3255-64
Nobre, Thatyane M; Martynowycz, Michael W; Andreev, Konstantin et al. (2015) Modification of Salmonella Lipopolysaccharides Prevents the Outer Membrane Penetration of Novobiocin. Biophys J 109:2537-2545
Li, Xian-Zhi; Plésiat, Patrick; Nikaido, Hiroshi (2015) The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria. Clin Microbiol Rev 28:337-418
Vargiu, Attilio V; Ruggerone, Paolo; Opperman, Timothy J et al. (2014) Molecular mechanism of MBX2319 inhibition of Escherichia coli AcrB multidrug efflux pump and comparison with other inhibitors. Antimicrob Agents Chemother 58:6224-34
Bansal-Mutalik, Ritu; Nikaido, Hiroshi (2014) Mycobacterial outer membrane is a lipid bilayer and the inner membrane is unusually rich in diacyl phosphatidylinositol dimannosides. Proc Natl Acad Sci U S A 111:4958-63
Opperman, Timothy J; Kwasny, Steven M; Kim, Hong-Suk et al. (2014) Characterization of a novel pyranopyridine inhibitor of the AcrAB efflux pump of Escherichia coli. Antimicrob Agents Chemother 58:722-33

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