Structure-Based Design of Non-Natural Amino Acid Inhibitors of Amyloid Fibrillation

Many globular and natively disordered proteins can convert into amyloid fibers. These fibers are associated with numerous pathologies1 as well as with normal cellular functions2,3, and frequently form during protein denaturation4,5. Inhibitors of pathological amyloid fibers could serve as leads for therapeutics, provided the inhibitors were specific enough to avoid interfering with normal processes. Here we show that computer-aided, structure-based design can yield highly specific peptide inhibitors of amyloid formation. Using known atomic structures of segments of amyloid fibers as templates, we have designed and characterized an all D-amino acid inhibitor of fibrillation of the tau protein found in Alzheimer’s disease, and a non-natural L-amino acid inhibitor of an amyloid fiber that enhances sexual transmission of HIV. Our results indicate that peptides from structure-based designs can disrupt the fibrillation of full-length proteins, including those like tau that lack fully ordered native structures.We thank M.I. Ivanova, J. Corn, T. Kortemme, D. Anderson, M.R. Sawaya, M. Phillips, S. Sambashivan, J. Park, M. Landau, Q. Zhang, R. Clubb, F. Guo, T. Yeates, J. Nowick, J. Zheng, and M.J. Thompson for discussions, HHMI, NIH, NSF, the GATES foundation, and the Joint Center for Translational Medicine for support, R. Peterson for help with NMR experiments, E. Mandelkow for providing tau constructs, R. Riek for providing amyloid beta, J. Stroud for amyloid beta preparation. Support for JK was from the Damon Runyon Cancer Research Foundation, for HWC by the Ruth L. Kirschstein National Research Service Award, for JM from the programme for junior-professors by the ministry of science, Baden-Württemberg, and for SAS by a UCLA-IGERT bioinformatics traineeship

Population Structure of Pseudomonas aeruginosa from Five Mediterranean Countries: Evidence for Frequent Recombination and Epidemic Occurrence of CC235

Several studies in recent years have provided evidence that Pseudomonas aeruginosa has a non-clonal population structure punctuated by highly successful epidemic clones or clonal complexes. The role of recombination in the diversification of P. aeruginosa clones has been suggested, but not yet demonstrated using multi-locus sequence typing (MLST). Isolates of P. aeruginosa from five Mediterranean countries (n = 141) were subjected to pulsed-field gel electrophoresis (PFGE), serotyping and PCR targeting the virulence genes exoS and exoU. The occurrence of multi-resistance (≥3 antipseudomonal drugs) was analyzed with disk diffusion according to EUCAST. MLST was performed on a subset of strains (n = 110) most of them had a distinct PFGE variant. MLST data were analyzed with Bionumerics 6.0, using minimal spanning tree (MST) as well as eBURST. Measurement of clonality was assessed by the standardized index of association (IAS). Evidence of recombination was estimated by ClonalFrame as well as SplitsTree4.0. The MST analysis connected 70 sequence types, among which ST235 was by far the most common. ST235 was very frequently associated with the O11 serotype, and frequently displayed multi-resistance and the virulence genotype exoS−/exoU+. ClonalFrame linked several groups previously identified by eBURST and MST, and provided insight to the evolutionary events occurring in the population; the recombination/mutation ratio was found to be 8.4. A Neighbor-Net analysis based on the concatenated sequences revealed a complex network, providing evidence of frequent recombination. The index of association when all the strains were considered indicated a freely recombining population. P. aeruginosa isolates from the Mediterranean countries display an epidemic population structure, particularly dominated by ST235-O11, which has earlier also been coupled to the spread of ß-lactamases in many countries

Synthese und Reaktionen von Alkoxycarbenkomplexen des Molybdaens

Available from TIB Hannover: DW 5346 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

eine prospektive Kohortenstudie

Objective: The Mental Adjustment to Cancer Scale (MAC scale) has evolved to a standard measure in the field of psycho-oncology. In this context an attitude called "fighting spirit" gained much attention as a coping style. Some reports suggest that coping efforts as measured by the MAC scale are predictive for survival of breast cancer patients. We explored the predictive power of the MAC scale by using a sample of patients with haematological malignancies undergoing allogenic hemopoietic stem cell transplantation (HSCT). Methods: Between 9/1999 and 12/2001 127 patients were administered the MAC scale prior to HSCT. Follow-up data of overall survival and event-free survival were obtained in December 2003 and analyzed using Cox-regression models. Results: At the time of the follow-up, 68 patients had died (overall survival), 75 patients had experienced a relapse or had died (event-free survival). We failed to find significant results for the MAC subscales with and without adjustment for prognostic factors. Conclusion: In the special situation of patients facing HSCT the MAC scale seems not to be of predictive value. In general, with respect to survival the empirical evidence is not very convincing.Zielsetzung: Die Mental Adjustment to Cancer Scale (MAC-Skala) hat sich im Feld der Psychoonkologie zu einem Standardmessinstrument entwickelt. In diesem Zusammenhang gewann ein als "fighting spirit" bezeichneter Bewältigungsstil breite Aufmerksamkeit. In manchen Studien wurde berichtet, dass mit der MAC-Skala erfasste Krankheitsverarbeitungsweisen mit späterer Überlebensdauer korreliert sind. Wir untersuchten die Vorhersagekraft der MAC-Skala in einer Stichprobe von Patienten mit hämatologischen Erkrankungen, die sich einer allogenen hämatopoietischen Stammzelltransplantation (HSZT) unterzogen. Methode: Zwischen 9/1999 und 12/2001 bearbeiteten 127 Patienten die MAC-Skala vor Durchführung der HSZT. Ein Follow-up im Hinblick auf Überlebenszeit erfolgte im Dezember 2003. Die Überlebenszeitdaten wurden mit Cox-Regressionsmodellen evaluiert. Ergebnisse: 68 Patienten waren verstorben, 75 Patienten waren verstorben oder erlitten Rezidiv. Es wurden mit und ohne Adjustierung bezüglich medizinischer Prognosefaktoren keine signifikanten Zusammenhänge einer der MAC-Subskalen mit der allgemeinen und der krankheitsfreien Überlebenszeit gefunden. Fazit: In der speziellen Situation vor HSZT scheint die MAC-Skala keinen Vorhersagewert für die Überlebenszeit zu haben. Jedoch gilt auch allgemein, dass die empirische Evidenz in dieser Hinsicht nicht überzeugend ist

Comparison between a basal-bolus and a premixed insulin regimen in individuals with type 2 diabetes-results of the GINGER study

Aim: To compare the efficacy and safety of an intensified insulin regimen, using insulin glargine (glargine) once daily and pre-meal insulin glulisine (glulisine) (basal-bolus), with a conventional therapy, using premixed insulin (premix) twice daily. Methods: This 52-week, open-label, randomized, multinational, multicentre trial included 310 subjects with type 2 diabetes (T2D) on premix, with or without metformin, who were randomized to a basal-bolus regimen with glargine and glulisine (n = 153; mean ± s.d. age 60.2 ± 7.5 years; HbA1c 8.6 ± 0.8%; weight 87.0 ± 15.1 kg; T2D duration 12.8 ± 5.8 years) or twice-daily premix (n = 157; age 60.9 ± 7.8 years; HbA1c 8.5 ± 0.9%; weight 84.3 ± 15.0 kg; T2D duration 12.5 ± 6.8 years). The primary endpoint was change in HbA1c from baseline to endpoint. Results: Mean decrease in baseline-to-endpoint HbA1c for basal-bolus vs. premix was −1.31 vs. −0.80% (difference: −0.476%; 95% Cl: −0.714, −0.238; p = 0.0001, ancova). More subjects reached HbA1c ≤ 7.0% in the basal-bolus group than in the premix group [68 (46.6%) vs. 43 (27.9%); p = 0.0004], while they also experienced significantly lower mean ± s.d. daytime (−2.7 ± 2.3 vs. −2.3 ± 2.5 mmol/l; p = 0.0033) and postprandial (−3.1 ± 2.6 vs. −2.5 ± 2.8 mmol/l; p < 0.0001) blood glucose. Endpoint daily insulin doses were 98.0 ± 48.7 vs. 91.3 ± 44.3 IU (p = 0.2104); mean weight gain was +3.6 ± 4.0 vs. +2.2 ± 4.5 kg (p = 0.0073). Mean number of overall hypoglycaemic events with basal-bolus and premix was 13.99 and 18.54 events/patient year, respectively (difference: −3.90; 95% CI: −10.40, 2.60; p = 0.2385). Conclusions: An intensified basal-bolus regimen using glargine/glulisine results in a significantly superior glycaemic control vs. premix therapy in a population with long-standing insulin-treated T2D, with no increase in the rates of hypoglycaemia