
	Where results make sense

Topic: Porins

In the News (Wed 15 Feb 12)

EXECUTIVE POWER

Iran

ANALYSIS

Pakistan

Family compact

	Lee M. Wetzler, M.D.
		A unique property of these porins is their ability to act as immune stimulators and augment the immune response to poorly immunogenic substances.
		Neisserial porin is also able to induce maturation of dendritic cells and improves their ability to present antigen to T cells.
		We are currently investigating the mechanism of this effect and have shown that it is due to an interaction of the porins with eukaryotic cell mitochondria and stabilization of the mitcochondrial membrane that is normally perturbed by apoptotic stimuli.
	www.bumc.bu.edu /Dept/Content.aspx?PageID=4670&departmentid=59 (568 words)

	CELL BIOLOGY 220 JMU (Site not responding. Last check: 2007-11-03)
		It may simply be more cost effective to put a few porins in these membranes then many more selective proteins.
		Below are two views of a model of porin from the bacterium Rhodopseudomonas blastica.
		In the left image the model is shown from the side as if you are in the middle of the membrane.
	csm.jmu.edu /biology/courses/bio220/porin.html (287 words)

	Identification and Characterization of a New Porin Gene of Klebsiella pneumoniae: Its Role in beta -Lactam Antibiotic ... (Site not responding. Last check: 2007-11-03)
		The arrow indicates the PCR fragment corresponding to the OmpK37 porin gene.
		Densitometric analysis results for the corresponding porin are indicated in arbitrary units at the bottom of each lane and are the mean ± the standard deviation of at least three independent experiments.
		pneumoniae porin (OmpK37, OmpK36, or OmpK35) on the outer membrane
	jb.asm.org /cgi/content/full/181/9/2726 (3879 words)

	OMP porins (Site not responding. Last check: 2007-11-03)
		Porins from the outer membrane of Gram-negative bacteria are generally non-selective, transmembrane channels.
		Omp F porin was first crystallized by R. Garavito in 1979.
		Pebay-Peyuola, E., Garavito, R.M., Rosenbusch, J.P., Zulauf, M., and Timmins, P.A. (1995) "Detergent structure in tetragonal crystals of porin from the outer membrtane of E. coli." Structure 3, 1051-1059.
	www.bch.msu.edu /labs/garavito/web/omp_porins.html (174 words)

	E.coli PhoE porin has an opposite voltage-dependence to the homologous OmpF
		Since porins strongly associate with each other and with LPS, it is likely that by using membrane fractions we can retain a proteinic and membrane environment around the channels that is closer to the natural one than if porins had been first purified.
		It is known that when both porin types are expressed, a mixture of homo- and heterotrimers exists in the membrane (Gehring and Nikaido, 1989).
		It is probably not a way to shut porins in case of wrongful insertion into the membrane (Nikaido, 1996), but rather to play the role of regulation of outer membrane permeability in specific conditions.
	www.nature.com /emboj/journal/v17/n1/full/7590750a.html (5953 words)

	Porins OmpC and PhoE of Escherichia coli as Specific Cell-surface Targets of Human Lactoferrin. BINDING CHARACTERISTICS ...
		Effect of hLf on the Permeability of Porins-- The effect of hLf on the channel conductance of OmpC, OmpF, and PhoE integrated in azolectin bilayers was studied.
		Binding of hLf to E. coli Porin-deficient Mutants-- To assess the role of OmpC or PhoE in binding hLf to the bacterial cell surface, the binding parameters of hLf to the isogenic
		Porins were pointed out as potential targets for the binding of Lf to the surface of Gram-negative bacteria (13).
	www.jbc.org /cgi/content/full/274/23/16107 (5248 words)

	Nonlinear and Asymmetric Open Channel Characteristics of an Ion-Selective Porin in Planar Membranes -- Mathes and ...
		Porins form large water-filled channels in the outer membrane and other diffusion barriers of the bacterial cell wall.
		Benz, R. Porin from bacterial and mitochondrial outer membranes.
		Asymmetry of orientation and voltage gating of the Acidovorax delafieldii porin Omp34 in lipid bilayers.
	www.biophysj.org /cgi/content/full/75/3/1255 (4611 words)

	Topological investigations of the FomA porin from Fusobacterium nucleatum and identification of the constriction loop ...
		Topological investigations of the FomA porin from Fusobacterium nucleatum and identification of the constriction loop L6 -- Kleivdal et al.
		Topological investigations of the FomA porin from Fusobacterium nucleatum and identification of the constriction loop L6
		Porin FomA in the outer membrane of Fusobacterium nucleatum
	mic.sgmjournals.org /cgi/content/abstract/147/4/1059 (348 words)

	Bacterial and Eukaryotic Porins - Structure, Function, Mechanism
		This first book dedicated to the topic relates the known physiological functions of porins to their molecular structure and mechanism, using various in vitro and in vivo methods.
		With 16 contributions by leading porin researchers, this reference is essential for biochemists, microbiologists, biotechnologists and physiologists.
		Porins of the Outer Membrane of Pseudomonas aeruginosa
	www.cplbookshop.com /contents/C1643.htm (177 words)

	Structural and Evolutionary Inference from Molecular Variation in Neisseria Porins -- Derrick et al. 67 (5): 2406 -- ... (Site not responding. Last check: 2007-11-03)
		to that of the Escherichia coli porins (9), with regions that
		The porin of Neisseria polysaccharea was excluded from the
		Topology of outer membrane porins in pathogenic Neisseria spp.
	iai.asm.org /cgi/content/full/67/5/2406 (4533 words)

	Asymmetric conductivity of engineered porins -- Bannwarth and Schulz 15 (10): 799 -- Protein Engineering Design and ...
		Statistics of the conduction increments on incorporation of porin molecules into a lipid bilayer, using 1 M KCl as the electrolyte and applying a voltage of 21 mV.
		On the left side wild-type porin and mutants InsA through InsE were added to the anode chamber (cis+), whereas on the right side they were added to the cathode chamber (cis–).
		Statistics of the conductivity events observed on porin incorporation from the anode chamber (cis+) into the lipid bilayer membrane with 1 M lithium acetate as the electrolyte and at a voltage of 53 mV.
	peds.oxfordjournals.org /cgi/content/full/15/10/799 (2297 words)

	Porins from Salmonella enterica serovar Typhimurium induce TNF-{alpha}, IL-6 and IL-8 release by CD14-independent and ...
		Porins from Salmonella enterica serovar Typhimurium induce TNF-{alpha}, IL-6 and IL-8 release by CD14-independent and CD11a/CD18-dependent mechanisms -- Galdiero et al.
		Porins from Salmonella enterica serovar Typhimurium induce TNF-
		Aldrich) was incubated with porins to neutralize the biological
	mic.sgmjournals.org /cgi/content/full/147/10/2697 (3663 words)

	Cutting Edge: Immune Stimulation by Neisserial Porins Is Toll-Like Receptor 2 and MyD88 Dependent -- Massari et al. 168 ...
		in the response to neisserial porins was investigated.
		of porin, as a pore-forming molecule in bacterial membranes,
		Neisserial porins induce B lymphocytes to express costimulatory B7-2 molecules and to proliferate.
	www.jimmunol.org /cgi/content/full/168/4/1533 (4661 words)

	Porins and Lipopolysaccharide Induce Apoptosis in Human Spermatozoa -- Gorga et al. 8 (1): 206 -- Clinical and ...
		Porins and Lipopolysaccharide Induce Apoptosis in Human Spermatozoa -- Gorga et al.
		Porin was extracted from Salmonella enterica serovar Typhimurium SH 5014 and Pasteurella multocida ATCC 6533 by the method
		The action of LPS porins and peptidoglycan fragments on human spermatozoa.
	cdli.asm.org /cgi/content/full/8/1/206 (1588 words)

	R.E.W. Hancock Laboratory: PORINS OF GRAM NEGATIVE BACTERIA
		Model membrane studies using liposomes and fl lipid bilayer membranes were utilized to characterize in detail a broad range of porins from Gram negative bacteria.
		A controversy in the literature had centred around whether or not OprF is the major porin for P. aeruginosa and whether the exclusion limit of the P.
		Sophisticated alignment and membrane topology predictions permitted alignment of OprD with the general porin superfamily, a first for a specific porin, and consequent prediction of a 2D membrane topology model.
	www.cmdr.ubc.ca /bobh/porins.html (1063 words)

	Lactoferrin
		OmpC and PhoE porins of Escherichia coli as specific cell-surface targets of human lactoferrin.
		Binding of human lactoferrin to Escherichia coli porins: a biochemical study.
		Porins OmpC and PhoE of E. coli as specific targets of human lactoferrin, binding
	members.aol.com /fsallmann/myhomepageindex2.html (363 words)

	Activity of nine antimicrobial agents against clinical isolates of Klebsiella pneumoniae producing extended-spectrum ...
		of porins causes a moderate increase in fluoroquinolone resistance.
		Porin expression in clinical isolates of Klebsiella pneumoniae.
		Roles of ß-lactamases and porins in activities of carbapenems and cephalosporins against Klebsiella pneumoniae.
	jac.oxfordjournals.org /cgi/content/full/46/5/858 (824 words)

	Porins from Salmonella enterica Serovar Typhimurium Activate the Transcription Factors Activating Protein 1 and ... (Site not responding. Last check: 2007-11-03)
		The porins were extracted as described by Nurminen (44).
		Haemophilus influenzae porin contributes to signaling of the inflammatory cascade in rat brain.
		Role of Pasteurella multocida porin on cytokine expression and release by murine splenocytes.
	iai.asm.org /cgi/content/full/70/2/558 (6601 words)

	Molecular Basis of Bacterial Outer Membrane Permeability Revisited -- Nikaido 67 (4): 593 -- Microbiology and Molecular ... (Site not responding. Last check: 2007-11-03)
		capsulatus trimeric porin (714-718), an achievement that was
		It is a trimeric porin, and the monomer folds as a 16-strand
		porins, on the basis of primary sequence alignment (774).
	mmbr.asm.org /cgi/content/full/67/4/593 (10180 words)

	Identification of positively charged residues of FomA porin of Fusobacterium nucleatum which are important for pore ...
		Cell envelope preparations, obtained from an equal amount of cells expressing rFomA porins, were heated in Laemmli sample buffer for 5 min at 95 °C before electrophoresis in a 10% polyacrylamide gel.
		The critical voltage values, reflecting at which transmembrane potential the rFomA porins started to close continuously, were measured by applying positive and negative voltage ramps as shown.
		The rate of uptake of two antibiotics for the wild-type rFomA porin was calculated, and those for the mutant FomA porins were expressed in percentage difference relative to the wild-type rFomA.
	content.febsjournal.org /cgi/content/full/260/3/818 (4405 words)

	Molecular and Cell Biology of a Family of Voltage-Dependent Anion Channel Porins in Lotus japonicus -- Wandrey et al. ...
		impaired in VDAC1, a porin of the mitochondrial outer membrane,
		Bathori G, Parolini I, Tombola F, Szabo I, Messina A, Oliva M, De Pinto V, Lisanti M, Sargiacomo M, Zoratti M (1999) Porin is present in the plasma membrane where it is concentrated in caveolae and caveolae-related domains.
		Lichtinger T, Burkovski A, Niederweis M, Kramer R, Benz R (1998) Biochemical and biophysical characterization of the cell wall porin of Corynebacterium glutamicum: the channel is formed by a low molecular mass polypeptide.
	www.plantphysiol.org /cgi/content/full/134/1/182 (5463 words)

	[Frontiers in Bioscience, 3, d1253-1261, December 15, 1998]
		Though there are examples of porins with considerable specificity for particular types of molecule, the common sort is relatively non-specific and allows passage of small hydrophilic molecules up to 5-600 Da in mass.
		It is not clear that the porin activity identified in M.smegmatis as active in planar lipid bilayers (26) is the same as the 40 kDa polypeptide active in the liposome swelling assay (27).
		The relative importance of diffusion through the outer permeability barrier and through porin channels is unknown for the majority of solutes; porin-negative mutants of mycobacteria (if viable) would be useful tools in exploring this important area.
	www.bioscience.org /1998/v3/d/draper/4.htm (1592 words)

	Pfam 18.0 : Porin_1 (Site not responding. Last check: 2007-11-03)
		Proteins, known as porins MEDLINE:2901351, are responsible for the 'molecular sieve' properties of the outer membrane.
		Some porins form general diffusion channels that allows any solutes up to a certain size (that size is known as the exclusion limit) to cross the membrane, while other porins are specific for a solute and contain a binding site for that solute inside the pores (these are known as selective porins).
		As porins are the major outer membrane proteins, they also serve as receptor sites for the binding of phages and bacteriocins.
	pfam.wustl.edu /cgi-bin/getdesc?name=Porin_1 (193 words)

	Neisseria meningitidis porin PorB interacts with mitochondria and protects cells from apoptosis -- Massari et al. 97 ...
		Neisserial porins are strong immune adjuvants and B cell activators.
		To investigate the fate of the porin in vitro, the subcellular localization of the porin was examined in several different
		The interaction of porin with target cells was examined by using epithelial and lymphoid cell lines.
	www.pnas.org /cgi/content/full/97/16/9070 (5772 words)

	Roles of beta -Lactamases and Porins in Activities of Carbapenems and Cephalosporins against Klebsiella pneumoniae -- ... (Site not responding. Last check: 2007-11-03)
		Roles of beta -Lactamases and Porins in Activities of Carbapenems and Cephalosporins against Klebsiella pneumoniae -- Martínez-Martínez et al.
		The role of porin OmpK36 expression in the resistance of
		A porin from Klebsiella pneumoniae: sequence homology, three-dimensional structure, and complement binding.
	aac.asm.org /cgi/content/full/43/7/1669 (3646 words)

	Altered expression of the ToxR-regulated porins OmpU and OmpT diminishes Vibrio cholerae bile resistance, virulence ...
		Altered expression of the ToxR-regulated porins OmpU and OmpT diminishes Vibrio cholerae bile resistance, virulence factor expression, and intestinal colonization -- Provenzano and Klose 97 (18): 10220 -- Proceedings of the National Academy of Sciences
		Altered expression of the ToxR-regulated porins OmpU and OmpT diminishes Vibrio cholerae bile resistance, virulence factor expression, and intestinal colonization
		Characterization of the Role of the ToxR-Modulated Outer Membrane Porins OmpU and OmpT in Vibrio cholerae Virulence
	www.pnas.org /cgi/content/abstract/97/18/10220 (913 words)

	The Vibrio cholerae Porins OmpU and OmpT Have Distinct Channel Properties -- Simonet et al. 278 (19): 17539 -- Journal ...
		OmpU and OmpT porins were specifically extracted at 3% Octyl-POE.
		Reconstitution in Liposomes-- Patch clamp experiments were performed on blisters induced from giant liposomes containing the reconstituted pure porin (21).
		Representative current traces obtained at the indicated pipette voltages in buffer A. The base line (BL) corresponds to the total current flowing through all open porins of the patch and is highlighted by a dotted line.
	www.jbc.org /cgi/content/full/278/19/17539 (5129 words)

	Wiley::Bacterial and Eukaryotic Porins: Structure, Function, Mechanism (Site not responding. Last check: 2007-11-03)
		This first book dedicated to the topic relates the known physiological functions of porins to their molecular structure and mechanism, as documented by various in vitro and in vivo methods, including the generation of null mutants in mice.
		For the first time, it brings together biophysical evidence with studies performed in a cellular context, presenting a unified picture of the fundamental importance of porins for cellular function.
		With 16 contributions by an interdisciplinary team of leading porin researchers, this reference is essential reading for every molecular or structural biologist with an interest in this essential protein family.
	www3.interscience.wiley.com:8100 /WileyCDA/WileyTitle/productCd-3527307753,subjectCd-LS30.html (198 words)

	Physics Today On The Web - Cover Story
		Scale drawing of Escherichia coli, showing one flagellum, truncated, and three porins (protein channels that allow the entry of water-soluble nutrients).
		A typical cell has up to six flagella and hundreds of porins.
		Information flows from the outside of the cell (shown at the top) by way of porins, the periplasmic space, and the cytoplasmic membrane, to the inside of the cell (shown at the bottom), and then to the flagellar motors (not shown).
	www.aip.org /pt/jan00/berg.htm (4402 words)

	porins - OneLook Dictionary Search (Site not responding. Last check: 2007-11-03)
		We found 2 dictionaries with English definitions that include the word porins:
		Tip: Click on the first link on a line below to go directly to a page where "porins" is defined.
		porins : Stedman's Online Medical Dictionary, 27th Edition [home, info]
	www.onelook.com /?w=porins (78 words)

	Ralf Koebnik
		Since 1990, I investigate the structure, function, assembly, and dynamics of bacterial outer membrane proteins.
		For this purpose, I used the proteins OmpA (a protein of structural importance), OmpF (a non-specific porin), LamB (a specific porin), and FhuA (a TonB-dependent receptor) from Escherichia coli as model systems.
		Phale, P.S., A. Philippsen, T. Kiefhaber, R. Koebnik, V.P. Phale, T. Schirmer, and J.P. Rosenbusch (1998): Stability of trimeric OmpF porin: the contributions of the latching loop L2.
	www.biologie.uni-halle.de /genet/plant/staff/koebnik/koebnik.html (992 words)

Try your search on: Qwika (all wikis)