Crystallization and preliminary X-ray diffraction analysis of L-aminoacylase from the hyperthermophilic archaeon Thermococcus litoralis.

Journal ArticleResearch Support, Non-U.S. Gov'tThe enzyme L-aminoacylase catalyses the hydrolysis of N-acyl-L-amino acids from peptides or proteins. The recombinant enzyme from the hyperthermophilic archaeon Thermococcus litoralis has been purified to homogeneity. This zinc-containing enzyme has been crystallized from ammonium sulfate using the sitting-drop vapour-diffusion method. The crystals diffract to 2.8 A resolution and belong to the rhombohedral space group R32, with unit-cell parameters a = b = 102.4, c = 178.5 A, gamma = 120 degrees in a hexagonal lattice setting. The asymmetric unit contains one enzyme monomer, containing a single zinc ion. Two synchrotron data sets have been collected at a remote wavelength and at the maximum f'wavelength for zinc. This has allowed the position of the metal to be identified in anomalous Patterson maps.BBSRCTMR/LSF programme to the EMBL Hamburg Outstatio

Essential and checkpoint functions of budding yeast ATM and ATR during meiotic prophase are facilitated by differential phosphorylation of a meiotic adaptor protein, Hop1

A hallmark of the conserved ATM/ATR signalling is its ability to mediate a wide range of functions utilizing only a limited number of adaptors and effector kinases. During meiosis, Tel1 and Mec1, the budding yeast ATM and ATR, respectively, rely on a meiotic adaptor protein Hop1, a 53BP1/Rad9 functional analog, and its associated kinase Mek1, a CHK2/Rad53-paralog, to mediate multiple functions: control of the formation and repair of programmed meiotic DNA double strand breaks, enforcement of inter-homolog bias, regulation of meiotic progression, and implementation of checkpoint responses. Here, we present evidence that the multi-functionality of the Tel1/Mec1-to-Hop1/Mek1 signalling depends on stepwise activation of Mek1 that is mediated by Tel1/Mec1 phosphorylation of two specific residues within Hop1: phosphorylation at the threonine 318 (T318) ensures the transient basal level Mek1 activation required for viable spore formation during unperturbed meiosis. Phosphorylation at the serine 298 (S298) promotes stable Hop1-Mek1 interaction on chromosomes following the initial phospho-T318 mediated Mek1 recruitment. In the absence of Dmc1, the phospho-S298 also promotes Mek1 hyper-activation necessary for implementing meiotic checkpoint arrest. Taking these observations together, we propose that the Hop1 phospho-T318 and phospho-S298 constitute key components of the Tel1/Mec1- based meiotic recombination surveillance (MRS) network and facilitate effective coupling of meiotic recombination and progression during both unperturbed and challenged meiosis

Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper Based Catalysts for CO2 Hydrogenation

Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface

Transplanting the leafy liverwort Herbertus hutchinsiae : A suitable conservation tool to maintain oceanic-montane liverwort-rich heath?

Thanks to the relevant landowners and managers for permission to carry out the experiments, Chris Preston for helping to obtain the liverwort distribution records and the distribution map, Gordon Rothero and Dave Horsfield for advice on choosing experimental sites and Alex Douglas for statistical advice. Juliane Geyer’s help with fieldwork was greatly appreciated. This study was made possible by a NERC PhD studentship and financial support from the Royal Botanic Garden Edinburgh and Scottish Natural Heritage.Peer reviewedPostprin

Use of intravenous immunoglobulin for the treatment of autoimmune encephalitis: audit of the NHS experience

OBJECTIVES: The treatments of limbic and other autoimmune encephalitis include immunosuppression, symptomatic treatment, and in the case of paraneoplastic syndromes, appropriate therapy for underlying neoplasms. When immunotherapy is considered, intravenous immunoglobulin is one option for treatment, either alone or in combination with corticosteroids. To date, however, evidence for the use of intravenous immunoglobulin in this context comes from case series/expert reviews as no controlled trials have been performed. We aimed to analyse the NHS England Database of intravenous immunoglobulin usage, which was designed to log use and guide procurement, to explore usage and therapeutic effect of intravenous immunoglobulin in autoimmune encephalitis in England. DESIGN: We conducted a retrospective audit and review of the NHS England Database on intravenous immunoglobulin use. Setting: NHS England Database of intravenous immunoglobulin use which covers secondary and tertiary care prescribing and use of intravenous immunoglobulin for all patients in hospitals in England. PARTICIPANTS: Hospital in-patients with confirmed or suspected autoimmune/limbic encephalitis between September 2010 and January 2017. RESULTS: A total of 625 patients who were 18 years of age or older were treated with intravenous immunoglobulin for autoimmune encephalitis, of whom 398 were determined as having 'highly likely' or 'definite' autoimmune/limbic encephalitis. Ninety-six percent were treated with a single course of intravenous immunoglobulin. The availability and accuracy of reporting of outcomes was very poor, with complete data only available in 27% of all cases. CONCLUSIONS: This is the first review of data from this unique national database. Whilst there was evidence for clinical improvement in many cases of patients treated with intravenous immunoglobulin, the quality of outcome data was generally inadequate. Methods to improve quality, accuracy and completeness of reporting are crucial to maximise the potential value of this resource as an auditing tool

Assessing the efficiency of mother-to-child HIV prevention in low- and middle-income countries using data envelopment analysis

AIDS is one of the most significant health care problems worldwide. Due to the difficulty and costs involved in treating HIV, preventing infection is of paramount importance in controlling the AIDS epidemic. The main purpose of this paper is to explore the potential of using Data Envelopment Analysis (DEA) to establish international comparisons on the efficiency of implementation of HIV prevention programmes. To do this we use data from 52 low- and middle-income countries regarding the prevention of mother-to-child transmission of HIV. Our results indicate that there is a remarkable variation in the efficiency of prevention services across nations, suggesting that a better use of resources could lead to more and improved services, and ultimately, prevent the infection of thousands of children. These results also demonstrate the potential strategic role of DEA for the efficient and effective planning of scarce resources to fight the epidemic