Investigations were undertaken to characterize the protective immunity induced by porin-lipopolysaccharide (LPS) against Salmonella typhimurium infection in mice. Mice immunized with porin-LPS showed higher levels of antiporin immunoglobulin G than mice which received porin alone. Further, T cells from porin-LPS-immunized mice showed an augmented proliferative response to porin in vitro compare...

BACKGROUND Bordetella pertussis infections continue to be a major public health challenge in Canada. Polymerase chain reaction (PCR) assays to detect B pertussis are typically based on the multicopy insertion sequence IS481, which offers high sensitivity but lacks species specificity. METHODS A novel B pertussis real-time PCR assay based on the porin gene was tested in parallel with several p...

Osmotic shock fluid of Escherichia coli exhibited pore-forming activity. This activity could be followed by an in vitro assay based on the conductivity increase for ions due to the presence of pores in black lipid membranes. The histogram (the distribution of conductivity increments in a single pore experiment) obtained with osmotic shock fluid from E. coli was identical to the histogram obtain...

OBJECTIVES The aim of this study was to investigate relatedness and molecular mechanism(s) of ertapenem resistance in clinical isolates of Klebsiella spp. (n = 28) and Enterobacter spp. (n = 27) referred from multiple hospitals to the UK national reference laboratory. METHODS Investigations included genotyping by PFGE, resistance gene analysis by PCR and antimicrobial susceptibility testing w...

We performed transposon mutagenesis of a two-color fluorescent reporter strain to identify new regulators of the porin genes ompF and ompC in Escherichia coli. Screening of colonies by fluorescence microscopy revealed numerous mutants that exhibited interesting patterns of porin expression. One mutant harbored an insertion in the gene encoding the histidine kinase CpxA, the sensor for a two-com...

Glyoxysomes of endosperm tissue of castor bean (Ricinus communis L.) seedlings were solubilized in a detergent and added to a lipid bilayer. Conductivity measurements revealed that the glyoxysomal preparation contained a porin-like channel. Using an electrophysiological method, which we established for semiquantitative determination of porin activity, we were able to demonstrate that glyoxysoma...

The Burkholderia cepacia epidemic strain marker (BCESM) is a useful epidemiological marker for virulent B. cenocepacia strains that infect patients with cystic fibrosis. However, there was no evidence that the original marker, identified by random amplified polymorphic DNA fingerprinting, contributed to pathogenicity. Here we demonstrate that the BCESM is part of a novel genomic island encoding...

Porin, also termed the voltage-dependent anion channel, is the most abundant protein of the mitochondrial outer membrane. The process of import and assembly of the protein is known to be dependent on the surface receptor Tom20, but the requirement for other mitochondrial proteins remains controversial. We have used mitochondria from Neurospora crassa and Saccharomyces cerevisiae to analyze the ...

Voltage-dependent anion channel (VDAC) has been suggested to be a mediator of mitochondrial-dependent cell death induced by Ca(2+) overload, oxidative stress and Bax-Bid activation. To confirm this hypothesis in vivo, we generated and characterized Drosophila VDAC (porin) mutants and found that Porin is not required for mitochondrial apoptosis, which is consistent with the previous mouse studie...

Porin (341 amino acids; mass of 37,782 Da) in the outer membrane of Haemophilus influenzae type b (Hib) permits diffusion into the periplasm of small solutes up to a molecular mass of 1400 Da. Molecular modeling of Hib porin identified its structural similarities to OmpF of Escherichia coli and disclosed for Hib porin a shorter length of loop 3 and a longer length of loop 4. By site-directed mu...