Topological dissection of the membrane transport protein Mhp1 derived from cysteine accessibility and mass spectrometry

Cys accessibility and quantitative intact mass spectrometry (MS) analyses have been devised to study the topological transitions of Mhp1, the membrane protein for sodium-linked transport of hydantoins from Microbacterium liquefaciens. Mhp1 has been crystallised in three forms (outward-facing open, outward-facing occluded with substrate bound, and inward-facing open). We show that one natural cysteine residue, Cys327, out of three, has an enhanced solvent accessibility in the inward-facing (relative to the outward-facing) form. Reaction of the purified protein, in detergent, with the thiol-reactive N-ethylmalemide (NEM), results in modification of Cys327, suggesting that Mhp1 adopts predominantly inward-facing conformations. Addition of either sodium ions or the substrate 5-benzyl-L-hydantoin (L-BH) does not shift this conformational equilibrium, but, systematic co-addition of the two results in an attenuation of labelling, indicating a shift toward outward-facing conformations that can be interpreted using conventional enzyme kinetic analyses. Such measurements can afford the Km for each ligand as well as the stoichiometry of ion-substrate coupled conformational changes. Mutations that perturb the substrate binding site either result in the protein being unable to adopt outward-facing conformations or in a global destabilisation of structure. The methodology combines covalent labeling, mass spectrometry and kinetic analyses in a straightforward workflow applicable to a range of systems, enabling the interrogation of changes in a protein’s conformation required for function at varied concentrations of substrates, and the consequences of mutations on these conformational transitions

On the price of morals in markets: an empirical study of the Swedish AP-Funds and the Norwegian Government Pension Fund

This study empirically analyses the exclusion of companies from investors’ investment universe due to a company’s business model (sector-based exclusion) or due to a company’s violations of international norms (normbased exclusion). We conduct a time-series analysis of the performance implications of the exclusion decisions of two leading Nordic investors, Norway’s Government Pension Fund-Global (GPFG) and Sweden’s AP-funds. We find that their portfolios of excluded companies do not generate an abnormal return relative to the funds’ benchmark index. While the exclusion portfolios show higher risk than the respective benchmark, this difference is only statistically significant for the case of GPFG. These findings suggest that the exclusion of the companies generally does not harm funds’ performance. We interpret these findings as indicative that with exclusionary screening, as practiced by the sample funds, asset owners can meet the ethical objectives of their beneficiaries without compromising financial returns

Adult mental health provision in England : a national survey of acute day units

Background Acute Day Units (ADUs) exist in some English NHS Trusts as an alternative to psychiatric inpatient admission. However, there is a lack of information about the number, configuration, and functioning of such units, and about the extent to which additional units might reduce admissions. This cross-sectional survey and cluster analysis of ADUs aimed to identify, categorise, and describe Acute Day Units (ADUs) in England. Methods English NHS Mental Health Trusts with ADUs were identified in a mapping exercise, and a questionnaire was distributed to ADU managers. Cluster analysis was used to identify distinct models of service, and descriptive statistics are given to summarise the results of the survey questions. Results Two types of service were identified by the cluster analysis: NHS (n = 27; and voluntary sector services (n = 18). Under a third of NHS Trusts have access to ADUs. NHS services typically have multi-disciplinary staff teams, operate during office hours, offer a range of interventions (medication, physical checks, psychological interventions, group sessions, peer support), and had a median treatment period of 30 days. Voluntary sector services had mostly non-clinically qualified staff, and typically offered supportive listening on a one-off, drop-in basis. Nearly all services aim to prevent or reduce inpatient admissions. Voluntary sector services had more involvement by service users and carers in management and running of the service than NHS services. Conclusions The majority of NHS Trusts do not provide ADUs, despite their potential to reduce inpatient admissions. Further research of ADUs is required to establish their effectiveness and acceptability to service users, carers, and staff

Nachweis von Zuckern aus Glykoproteiden des Magensaftes bei normaler Magenschleimhaut und chronischer Gastritis

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