The Uppsala Electron Density Server (EDS; http:// eds.bmc.uu.se/) is a web-based facility that provides access to electron-density maps and statistics concerning the ®t of crystal structures and their maps. Maps are available for $87% of the crystallographic Protein Data Bank (PDB) entries for which structure factors have been deposited and for which straightforward map calculations succeed in reproducing the published R value to within ®ve percentage points. Here, an account is provided of the methods that are used to generate the information contained in the server. Some of the problems that are encountered in the map-generation process as well as some spin-offs of the project are also discussed.

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Our results indicate that PAE provides a clinically and statistically significant improvement in symptoms and QoL, although some of these improvements were greater in the TURP arm. The safety profile and quicker return to normal activities may be seen as highly beneficial by patients considering PAE as an alternative treatment to TURP, with the concomitant advantages of reduced length of hospital stay and need for admission after PAE. PAE is an advanced embolization technique demanding a high level of expertise, and should be performed by experienced interventional radiologists who have been trained and proctored appropriately. The use of cone-beam computed tomography is encouraged to improve operator confidence and minimize non-target embolizations. The place of PAE in the care pathway is between that of drugs and surgery, allowing the clinician to tailor treatment to individual patients' symptoms, requirements and anatomical variation.

A publicly available web-based interface is presented for producing high-quality ray-traced images and movies from the molecular-modelling program O [Jones et al. (1991), Acta Cryst. A47, 110-119]. The interface allows the user to select O-plot files and set parameters to create standard input files for the popular ray-tracing renderer POV-Ray, which can then produce publication-quality still images or simple movies. To ensure ease of use, we have made this service available to the O user community via the World Wide Web. The public Molray server is available at http://xray.bmc.uu.se/molray.

Loss of mannosylphosphate from Candida albicans cell wall proteins results in enhanced resistance to the inhibitory effect of a cationic antimicrobial peptide via reduced peptide binding to the cell surface The outermost layer of the Candida albicans cell wall is enriched with mannosylated glycoproteins. We have used a range of isogenic glycosylation mutants of C. albicans, which are defective to varying degrees in cell wall protein mannosylation, to investigate the role of the outermost layer of the yeast cell wall in mediating the fungicidal action of the cationic, a-helicalThe degree of phosphomannan loss, and concomitant reduction in surface negative charge, from the series of glycosylation mutants correlated with reduced levels of peptide binding to the cells. In turn, the reduced peptide binding correlated with enhanced resistance to DsS3(1-16). To ascertain whether DsS3(1-16) binds to negatively charged phosphate, we studied the effect of exogenous glucosamine 6-phosphate, and glucosamine hydrochloride as a negative control, on the antifungal efficacy of DsS3(1-16). Glucosamine 6-phosphate retarded the efficacy of DsS3(1-16), and this was attributed to the presence of phosphate, because addition of identical concentrations of glucosamine hydrochloride had little detrimental effect on peptide efficacy. Fluorescence microscopy with DsS3(1-16) tagged with fluorescein revealed that the peptide binds to the outer surface of the yeast cell, supporting our previous conclusion that the presence of exterior phosphomannan is a major determinant of the antifungal potency of DsS3(1-16). The binding of the peptide to the cell surface was a transient event that was followed by apparent localization of DsS3(1-16) in the vacuole or dissemination throughout the entire cytosol. The presence of glucosamine 6-phosphate clearly reduced the proportion of cells in the population that showed complete cytosolic staining, implying that the binding and entry of the peptide into the cytosol is significantly reduced due to the exogenous phosphate sequestering the peptide and reducing the amount of peptide able to bind to the surface phosphomannan. In conclusion, we present evidence that an antimicrobial peptide, similar to those employed by cells of the human immune system, has evolved to recognize molecular patterns on the surface of pathogens in order to maximize efficacy. INTRODUCTIONOver the past 30 years there has been a significant increase in the number of life-threatening fungal infections (Edmond et al., 1999;Enoch et al., 2006

In this paper, a simple and sensitive approach for human epidermal growth factor receptor 2 (HER2) detection is presented, using antibody-functionalised magnetic beads coupled to screenprinted cells. The immunoassay is based on a sandwich format in which a primary monoclonal antibody anti-HER2 is coupled to protein A modified magnetic beads. The modified beads are then used to capture the protein from the sample solution and a sandwich assay is performed by adding a secondary monoclonal antibody anti-HER2 labelled with biotin. The enzyme alkaline phosphatase (AP) conjugated with streptavidin and its substrate (-naphthyl-phosphate) are then used for the electrochemical detection by differential pulse voltammetry (DPV). The experimental conditions for the immunoassay were optimised. The performance of the assay in terms of sensitivity, reproducibility and selectivity has been studied in buffer and serum samples.

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The crystal structures of Family 7 glycohydrolases suggest that a histidine residue near the acid/base catalyst could account for the higher pH optimum of the Humicola insolens endoglucanase Cel7B, than the corresponding Trichoderma reesei enzymes. Modelling studies indicated that introduction of histidine at the homologous position in T. reesei Cel7A (Ala(224)) required additional changes to accommodate the bulkier histidine side chain. X-ray crystallography of the catalytic domain of the E223S/A224H/L225V/T226A/D262G mutant reveals that major differences from the wild-type are confined to the mutations themselves. The introduced histidine residue is in plane with its counterpart in H. insolens Cel7B, but is 1.0 A (=0.1 nm) closer to the acid/base Glu(217) residue, with a 3.1 A contact between N(epsilon2) and O(epsilon1). The pH variation of k(cat)/K(m) for 3,4-dinitrophenyl lactoside hydrolysis was accurately bell-shaped for both wild-type and mutant, with pK(1) shifting from 2.22+/-0.03 in the wild-type to 3.19+/-0.03 in the mutant, and pK(2) shifting from 5.99+/-0.02 to 6.78+/-0.02. With this poor substrate, the ionizations probably represent those of the free enzyme. The relative k(cat) for 2-chloro-4-nitrophenyl lactoside showed similar behaviour. The shift in the mutant pH optimum was associated with lower k(cat)/K(m) values for both lactosides and cellobiosides, and a marginally lower stability. However, k(cat) values for cellobiosides are higher for the mutant. This we attribute to reduced non-productive binding in the +1 and +2 subsites; inhibition by cellobiose is certainly relieved in the mutant. The weaker binding of cellobiose is due to the loss of two water-mediated hydrogen bonds.