Stability mechanisms of a thermophilic laccase probed by molecular dynamics.

Laccases are highly stable, industrially important enzymes capable of oxidizing a large range of substrates. Causes for their stability are, as for other proteins, poorly understood. In this work, multiple-seed molecular dynamics (MD) was applied to a Trametes versicolor laccase in response to variable ionic strengths, temperatures, and glycosylation status. Near-physiological conditions provided excellent agreement with the crystal structure (average RMSD ∼0.92 Å) and residual agreement with experimental B-factors. The persistence of backbone hydrogen bonds was identified as a key descriptor of structural response to environment, whereas solvent-accessibility, radius of gyration, and fluctuations were only locally relevant. Backbone hydrogen bonds decreased systematically with temperature in all simulations (∼9 per 50 K), probing structural changes associated with enthalpy-entropy compensation. Approaching T opt (∼350 K) from 300 K, this change correlated with a beginning "unzipping" of critical β-sheets. 0 M ionic strength triggered partial denucleation of the C-terminal (known experimentally to be sensitive) at 400 K, suggesting a general salt stabilization effect. In contrast, F(-) (but not Cl(-)) specifically impaired secondary structure by formation of strong hydrogen bonds with backbone NH, providing a mechanism for experimentally observed small anion destabilization, potentially remedied by site-directed mutagenesis at critical intrusion sites. N-glycosylation was found to support structural integrity by increasing persistent backbone hydrogen bonds by ∼4 across simulations, mainly via prevention of F(-) intrusion. Hydrogen-bond loss in distinct loop regions and ends of critical β-sheets suggest potential strategies for laboratory optimization of these industrially important enzymes

Gender differences in respiratory symptoms in 19-year-old adults born preterm

Objective: To study the prevalence of respiratory and atopic symptoms in (young) adults born prematurely, differences between those who did and did not develop Bronchopulmonary Disease (BPD) at neonatal age and differences in respiratory health between males and females. Methods: Design: Prospective cohort study. Setting: Nation wide follow-up study, the Netherlands. Participants: 690 adults (19 year old) born with a gestational age below 32 completed weeks and/or with a birth weight less than 1500g. Controls were Dutch participants of the European Community Respiratory Health Survey (ECRHS). Main outcome measures: Presence of wheeze, shortness of breath, asthma, hay fever and eczema using the ECRHS-questionnaire

No association between glucocorticoid receptor polymorphisms and long-term respiratory outcome after very preterm birth

Developmen

Enigmatic Gratuitous Induction of the Covalent Flavoprotein Vanillyl-Alcohol Oxidase in Penicillium simplicissimum

When Penicillium simplicissimum is grown on veratryl alcohol, anisyl alcohol, or 4-(methoxymethyl)phenol, an intracellular covalent flavin-containing vanillyl-alcohol oxidase is induced. The induction is highest (up to 5% of total protein) during the growth phase. In addition to vanillyl-alcohol oxidase, an intracellular catalase-peroxidase is induced. Induction of vanillyl-alcohol oxidase in P. simplicissimum is prevented by the addition of isoeugenol to veratryl alcohol-containing media, but growth is unaffected. The inhibitory effect of isoeugenol on induction is not observed when anisyl alcohol or 4-(methoxymethyl)phenol is used as the growth substrate. Based on the induction experiments and the degradation pathways for veratryl and anisyl alcohol, we propose that induction of vanillyl-alcohol oxidase is superfluous when P. simplicissimum is grown on these aromatic alcohols. However, the enzyme plays an essential role in the degradation of the methyl ether of p-cresol, 4-(methoxymethyl)phenol

"I have got diabetes!" - Interviews of patients newly diagnosed with type 2 diabetes

Background: To be diagnosed with type 2 diabetes is a challenge for every patient. There are previous studies on patients' experience in general but not addressing the increased cardiovascular risk and multifactorial treatment. The aim of this study was to explore the thoughts, experiences and reactions of newly diagnosed patients with diabetes to this diagnosis and to the risk of developing complications. Methods: Ten adults (7 men/3 women, aged 50-79) diagnosed with type 2 diabetes within the last 12 months were interviewed at a primary health care center in Sweden. An interview guide was used in the semi-structured interviews that were transcribed verbatim. The analysis was qualitative and inspired by systematic text condensation (Malterud). The text was read several times and meaning units were identified. Related meaning units were sorted into codes and related codes into categories during several meetings between the authors. Finally, the categories were merged and formed themes. Results: We defined three main themes: Reaction to diagnosis, Life changes and Concerns about the future. Most patients reacted to the diagnosis without intensive feelings. Lifestyle changes were mainly accepted but hard to achieve. The patients' major concerns for the future were the consequences for daily life (being able to drive and read) and concerns for relatives rather than anxieties regarding medical issues such as laboratory tests. There were considerable differences in how much patients wanted to know about their future risks. Conclusions: The results of this study might help to focus doctor-patient communication on issues highlighted by the patients and on the importance of individualizing information and recommendations for each patient

Comparison of three microbial screening methods for antibiotics using routine monitoring samples

Monitoring large numbers of slaughter animals for the presence of antimicrobial residues is preferably carried out using microbiological screening methods, because of their high cost-effectiveness. An evaluation of the Nouws antibiotic test (NAT) was performed on routine monitoring samples and the performance of the method was compared with two other microbial screening methods: Screening test for antibiotic residues (STAR) and Premi®Test. Analysis of 591 samples yielded four MRL violations. Three of them concerned tetracyclines that were only detected with the NAT and the STAR method. The fourth, 172 µg kg-1 Sulfadiazine, was detected by all three methods. Additionally, 156 µg kg-1 Tulathromycin was found in porcine meat, while for this residue no MRL in muscle has been established