An artificial neural network (NN) was trained to predict the topology of bacterial outer membrane (OM) beta-strand proteins. Specifically, the NN predicts the z-coordinate of Calpha atoms in a coordinate frame with the outer membrane in the xy-plane, such that low z-values indicate periplasmic turns, medium z-values indicate transmembrane beta-strands, and high z-values indicate extracellular l...

TolB is a periplasmic protein of the cell envelope Tol complex. It is partially membrane associated through an interaction with the outer membrane lipoprotein PAL (peptidoglycan-associated lipoprotein), which also belongs to the Tol system. The interaction of TolB with outer membrane porins of Escherichia coli was investigated with a purified TolB derivative harboring a six-histidine tag. TolB ...

Neisserial porins are strong immune adjuvants and B cell activators. The effect of neisserial porin PorB on activation-induced cell death was investigated, as a potential additional mechanism of the porin's immunopotentiating ability. Neisserial porins interact with target cells to localize intracellularly in the mitochondrial compartment without negatively affecting cellular survival. Pretreat...

Voltage-dependent anion channels (VDACs) are pore-forming proteins (porins) that form the major pathway for movement of adenine nucleotides through the outer mitochondrial membrane. Electrophysiological studies indicate that VDAC-like channel activity is also prevalent in the cell membranes of many mammalian cells. However, the multitopological localization of porins outside the mitochondrion h...

Mitochondrial outer membrane permeability is conferred by a family of porin proteins. Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals. Because mitochondrial porins have significant roles in diverse cellular processes including regulation of mitochondrial ATP and calcium flux, we sought to d...

A simple procedure for obtaining surface exposed antigens of Salmonella Enteritidis is described. A heat treatment of whole bacteria in saline solution induced the release of small membrane vesicles containing outer membrane components as well as surface appendage components, such as fimbriae and flagellin. The characterization of the structural components of this extract, called HE, was establ...

The movement of small molecules and ions across the outer membrane of gram-negative bacteria is mediated by a class of major proteins named porins (1). The porins form generally large water-filled pores with a diameter of 1.3-2.3 nm in the outer membrane (1) and in lipid bilayer membranes (2). These pores have a defined exclusion limit for hydrophilic solutes (3). A new outer membrane protein h...

PURPOSE Porins are outer membrane protein (OMP) that form water filled channels that permit the diffusion of small hydrophilic solutes like beta-lactam antibiotics across the outer membrane. Two major porins that facilitate diffusion of antimicrobials have been described in Klebsiella spp. and Escherichia coli. The present study was carried out to examine the role of porins among Extended Spect...

Many bacteria rely on siderophores to extract iron from the environment. However, acquisition of iron-loaded siderophores is dependent on high-affinity uptake systems that are not produced under high-iron conditions. The fact that bacteria are able to maintain iron homeostasis in the absence of siderophores indicates that alternative iron acquisition systems exist. It has been speculated that s...