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Functionalised emulsion-templated polymers (PolyHIPEs) are reported as new materials for electroanalytical applications. PolyHIPEs, which are prepared from high internal phase emulsions (HIPEs), were tailored by optimisation of polymerisation conditions to yield well-defined, tubular, porous membranes. The PolyHIPE membrane backbone was activated by incorporating ionophores, graphite particles, electron mediators and enzymes. The results show that a valinomycin ionophore impregnated, plasticised membrane shows a Nernstian response to K + ions with improved detection limits and selectivity coefficients compared to traditional PVC membranes. The graphite/mediator/enzyme loaded membranes exhibit quasi-reversible redox behaviour with semi-infinite linear diffusion at fast scan rates tending to radial diffusion at slow scan rates. Additionally, composite, asymmetric membrane structures with a porous PolyHIPE membrane and a PVC membrane exclude proteins such as BSA (bovine serum albumin) and a 1 acid glycoprotein (AAG). These preliminary results demonstrate that plasticised membranes with functionalised skeletons and with controllable porosity such as PolyHIPE membranes are very promising for the fabrication of sensors with integrated separation.

Endoplasmic reticulum oxidoreductases (Eros) are essential for the formation of disulfide bonds. Understanding disulfide bond catalysis in mammals is important because of the involvement of protein misfolding in conditions such as diabetes, arthritis, cancer, and aging. Mammals express two related Ero proteins, Ero1␣ and Ero1␤. Ero1␤ is incompletely characterized but is of physiological interest because it is induced by the unfolded protein response. Here, we show that Ero1␤ can form homodimers and mixed heterodimers with Ero1␣, in addition to Ero-PDI dimers. Ero-Ero dimers require the Ero active site, occur in vivo, and can be modeled onto the Ero1p crystal structure. Our data indicate that the Ero1␤ protein is constitutively strongly expressed in the stomach and the pancreas, but in a cell-specific fashion. In the stomach, selective expression of Ero1␤ occurs in the enzyme-producing chief cells. In pancreatic islets, Ero1␤ expression is high, but is inversely correlated with PDI and PDIp levels, demonstrating that cell-specific differences exist in the regulation of oxidative protein folding in vivo.Protein folding in the ER 5 attracts considerable interest because the failure of a protein to fold can lead to a host of genetic and acquired diseases (1), ranging from cystic fibrosis to ␣1 anti-trypsin deficiency (2). Professional secretory cells in particular must regulate the synthesis of their ER membranes and chaperones to cope with the demands of increased protein production. This is achieved through ER to nucleus signaling pathways, mediated by the trans-membrane associated proteins Ire1␣, PERK, and ATF6 (3). ATF6 and Ire1␣ induce the transcription of XBP1 and the splicing of its mRNA, culminating in the expression of UPR target genes (4). XBP1 is required for B cell maturation into antibody-producing plasma cells (5), and recently, XBP1 and chronic unfolded protein responses have been implicated in obesity and the onset of type 2 diabetes (6), suggesting that targeting physiological unfolded protein responses may have therapeutic value in this disease.Disulfide bond formation is an essential component of the protein folding process, and disulfide bonds are required for structural stability, enzymatic function, and regulation of protein activity (7). The catalytic events involving the oxidation, reduction, and isomerization of disulfide bonds take place in the ER. During protein oxidation, PDI introduces native disulfide bonds into substrate proteins, and is reoxidized by the Ero proteins (Ero1p in yeast, Ero1␣ and Ero1␤ in humans) (8 -11). In yeast, Pdi1p is capable of both oxidizing and isomerizing disulfide bonds, although the relative importance of each function has been debated (12). In humans, PDI also contributes to collagen biosynthesis as a component of the prolyl-4-hydroxlase complex (13) and can act as a component of the ER degradation machinery, particularly with respect to the unfolding and retro-translocation of toxins (14). Numerous PDI homologues exist in yeast (Mpd1p, Mpd2p, Eps1p, and Eug...

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The metal-based emission of a series of luminescent europium and terbium complexes incorporating an aromatic chromophore is rendered pH-dependent either through perturbation of the aryl singlet or triplet energy or by modulating the degree of quenching of the lanthanide excited state. Systems exhibiting each of these pathways have been incorporated in thin-film sol gel matrixes and evaluated as pH sensors in static and flow analyses at constant ionic strength. pH-dependent intensity or ratiometric methods, for emission or excitation spectra, have been defined for lanthanide complexes incorporating substituted phenanthridine (pK(a) from ca. 6.8 to 7.2) or 6-cyanophenanthridine-2-sulfonyl chromophores (pK(a) approximately 7.14 in human serum solution) (lambda(exc) 365 nm, phi H(2)O = 7.2%).

Lysine is a precursor for the synthesis of an aminobutyl C-functionalised tetra-azacyclododecane tetra-acid which has been linked to 872.3 antibody and may be labelled with 9OY to form a kinetically stable complex of potential use in radio i m mu not h e ra py .

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The synthesis of the ligands 1 -aza-4,7-dithiacyclononane, N,N'-lr2-bis(l -aza-4,7-dithiacyclononyl)ethane, and 1,10-dithia-4,7,13,16-tetra-azacyclo-octadecane and their silver( I) complexes are reported. Stability constants in water and methanol have been determined using pH-metric methods, and enthalpies of complexation measured calorimetrically in methanol. The N-alkyl derivatives show enhanced enthalpies of complexation, but exhibit unfavourable entropies of complexation. Crystal structures of the [18] -N,S2 and bis[9] -NS2 silver complexes reveal distorted octahedral co-ordination geometry, although in aqueous solution the bis[9] -NS, silver complex does not adopt the sandwich structure revealed in the crystallographic analysis.