Pore-forming proteins play critical roles in pathogenic attack and immunological defence. The membrane attack complex/perforin (MACPF) group of homologues represents, with cholesterol-dependent cytolysins, the largest family of such proteins. In this review, we begin by describing briefly the structure of MACPF proteins, outlining their common mechanism of pore formation. We subsequently discus...

We study the nature of non-Fickian particle transport in 3-D porous media by simulating fluid flow in the intricate pore space of real rock. We solve the full Navier-Stokes equations at the same resolution as the 3-D micro-CT (computed tomography) image of the rock sample and simulate particle transport along the streamlines of the velocity field. We find that transport at the pore scale is mar...

The structure of the pore region of the alpha subunit of the bovine rod cyclic nucleotide-gated channel was probed using cysteine-scanning mutagenesis and hydrophilic sulfhydryl-reactive methanethiosulfonate (MTS) reagents. A region homologous to the pore helix in the X-ray crystal structure of the KcsA K(+) channel showed a helical pattern of reactivity with externally applied MTS reagents. Su...

The ligand binding domain of glutamate receptors (GluRs) has 2-fold rotational symmetry. The structure including the symmetry of the GluR ion channel remains undefined. Here we used substituted cysteines in the pore-lining M3 segment of the AMPAR GluR-A subunit and various cysteine-reactive agents to study the structure of the channel during gating. We find that cysteines substituted at A+6, lo...

Pore-blocking toxins inhibit voltage-dependent K(+) channels (Kv channels) by plugging the ion-conduction pathway. We have solved the crystal structure of paddle chimera, a Kv channel in complex with charybdotoxin (CTX), a pore-blocking toxin. The toxin binds to the extracellular pore entryway without producing discernable alteration of the selectivity filter structure and is oriented to projec...

The Kir3.1 K(+) channel participates in heart rate control and neuronal excitability through G-protein and lipid signaling pathways. Expression in Escherichia coli has been achieved by replacing three fourths of the transmembrane pore with the pore of a prokaryotic Kir channel, leaving the cytoplasmic pore and membrane interfacial regions of Kir3.1 origin. Two structures were determined at 2.2 ...

Porous solids have an important role in addressing some of the major energy-related problems facing society. Here we describe a porous solid, α-MnO2, with a hierarchical tetramodal pore size distribution spanning the micro-, meso- and macro pore range, centred at 0.48, 4.0, 18 and 70  nm. The hierarchical tetramodal structure is generated by the presence of potassium ions in the precursor solut...

In the neuron, early neurotransmitters are released through the fusion pore prior to the complete vesicle fusion. It has been thought that the fusion pore is a gap junction-like structure made of transmembrane domains (TMDs) of soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins. However, evidence has accumulated that lipid mixing occurs prior to the neurotran...

Equation of state and structure of hard-sphere fluids confined in a cylindrical hard pore were investigated at the vicinity of fluid-solid transition via molecular dynamics simulation. By constructing artificial closed-packed structures in a cylindrical pore, we explicitly capture the fluid-solid phase transition and coexistence for the pore diameters from 2.17sigma to 15sigma. There exist some...

Synthesis of mesoporous materials with a bimodal pore size has always been of great importance for size-selective separation process. Especially, ordered mesoporous cubic MCM-48 with its highly interwoven and branched pore structure, is a potential separation material in applications similar to which zeolites are now being used. This material could have specific technological advantages because...