Silicon (Si) has long been known to play a major physiological and structural role in certain organisms, including diatoms, sponges, and many higher plants, leading to the recent identification of multiple proteins responsible for Si transport in a range of algal and plant species. In mammals, despite several convincing studies suggesting that silicon is an important factor in bone development ...

Combination of standard approaches like pepsin digestion and slab gel electrophoresis with capillary separations allows a relatively easy identification of in vivo occurring collagen fragments. Capillary electrophoresis can be done either in 25 mM phosphate buffer (pH 2.5) or in a 25 mM phosphate buffer (pH 4.5) made 0.1% with respect to sodium dodecyl sulfate (SDS). While in the first case pep...

We describe a fluorogenic two-site noncompetitive heterogeneous immunoassay with magnetic beads on a low-voltage digital microfluidic platform using closed electrowetting-on-dielectric (EWOD). All the steps of an enzyme-linked immunosorbent assay (ELISA) were performed on the device using 9H-(1, 3-dichloro-9, 9-dimethylacridin-2-one-7-yl) phosphate as the fluorogenic substrate for the enzyme al...

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...

This article deals with modelling the simultaneous uptake of water and highly buffered nutrient, such as phosphate, by root branching structures from partially saturated soil. We use the simultaneous water and nutrient uptake model to investigate the effect that water movement has on nutrient uptake. With the aid of this model we are also able to show that the previous models by Barber and Tink...

The major facilitator superfamily represents the largest group of secondary active membrane transporters in the cell. The 3.3A resolution structure of a member of this protein superfamily, the glycerol-3-phosphate transporter from the Escherichia coli inner membrane, reveals two domains connected by a long central loop. These N- and C-terminal domains, each containing a six-helix bundle, are re...

The λ exonuclease is an ATP-independent enzyme that binds to dsDNA ends and processively digests the 5'-ended strand to form 5' mononucleotides and a long 3' overhang. The crystal structure of λ exonuclease revealed a toroidal homotrimer with a central funnel-shaped channel for tracking along the DNA, and a mechanism for processivity based on topological linkage of the trimer to the DNA was pro...

Midazolam is widely used as a sedative agent to produce amnesia in patients undergoing fibre-optic bronchoscopy. However, if a patient does not receive sufficient local anaesthesia, continuous severe cough and physical movement may interrupt the procedure and reduce its safety. We therefore examined whether codeine phosphate is a useful premedication for bronchoscopy. The study design was a ran...

Galactitol-1-phosphate 5-dehydrogenase (GPDH) is a polyol dehydrogenase that belongs to the medium-chain dehydrogenase/reductase (MDR) superfamily. It catalyses the Zn(2+)- and NAD(+)-dependent stereoselective dehydrogenation of L-galactitol 1-phosphate to D-tagatose 6-phosphate. Here, three crystal structures of GPDH from Escherichia coli are reported: that of the open state of GPDH with Zn(2+...

Cytoplasmic transport is mediated by a group of molecular motors that typically work in isolation, under conditions where they must move their cargos long distances without dissociating from their tracks. This processive behavior requires specific adaptations of motor enzymology to meet these unique physiologic demands. One of these involves the ability of the two heads of a processive motor to...