A Peptide Analogue to a Fusion Domain Within Photoreceptor Peripherin/rds Promotes Membrane Adhesion and Depolarization

Photoreceptor peripherin/rds promotes membrane fusion, through a putative fusion domain located within the C-terminus (Boesze-Battaglia et al., Biochemistry 37 (1998) 9477-9487). A peptide analogue to this region, PP-5, competitively inhibits peripherin/rds mediated fusion in a cell free assay system. To characterize how this region is involved in the fusion process we investigated two of the individual steps in membrane fusion, membrane adhesion and membrane destabilization inferred from depolarization studies. Membrane depolarization was measured as the collapse of a valinomycin induced K+ diffusion potential in model membranes, using a potential sensitive fluorescent probe, diS-C2-5. PP-5 induced membrane depolarization in a concentration dependent manner. PP-5 has been shown by Fourier transform infrared spectroscopy to be an amphiphilic α-helix. Therefore, the requirement for an amphiphilic α-helix to promote depolarization was tested using two mutant peptides designed to disrupt either the amphiphilic nature of PP-5 (PP-5AB) or the α-helical structure (PP-5HB). PP-5AB inhibited PP-5 induced depolarization when added in an equimolar ratio to PP-5. Neither mutant peptide alone or in combination with PP-5 had any effect on calcium dependent vesicle aggregation. Using non-denaturing gel electrophoresis and size exclusion chromatography techniques PP-5 was shown to form a tetrameric complex. Equimolar mixtures of PP-5 and PP-5AB formed a heterotetramer which was unable to promote membrane depolarization. The hypothesis that PP-5 tetramers promote membrane depolarization is consistent with the calculated Hill coefficient of 3.725, determined from a Hill analysis of the depolarization data. Copyright (C) 2000 Elsevier Science B.V

A Peptide Analogue to a Fusion Domain Within Photoreceptor Peripherin/rds Promotes Membrane Adhesion and Depolarization

Photoreceptor peripherin/rds promotes membrane fusion, through a putative fusion domain located within the C-terminus (Boesze-Battaglia et al., Biochemistry 37 (1998) 9477-9487). A peptide analogue to this region, PP-5, competitively inhibits peripherin/rds mediated fusion in a cell free assay system. To characterize how this region is involved in the fusion process we investigated two of the individual steps in membrane fusion, membrane adhesion and membrane destabilization inferred from depolarization studies. Membrane depolarization was measured as the collapse of a valinomycin induced K+ diffusion potential in model membranes, using a potential sensitive fluorescent probe, diS-C2-5. PP-5 induced membrane depolarization in a concentration dependent manner. PP-5 has been shown by Fourier transform infrared spectroscopy to be an amphiphilic α-helix. Therefore, the requirement for an amphiphilic α-helix to promote depolarization was tested using two mutant peptides designed to disrupt either the amphiphilic nature of PP-5 (PP-5AB) or the α-helical structure (PP-5HB). PP-5AB inhibited PP-5 induced depolarization when added in an equimolar ratio to PP-5. Neither mutant peptide alone or in combination with PP-5 had any effect on calcium dependent vesicle aggregation. Using non-denaturing gel electrophoresis and size exclusion chromatography techniques PP-5 was shown to form a tetrameric complex. Equimolar mixtures of PP-5 and PP-5AB formed a heterotetramer which was unable to promote membrane depolarization. The hypothesis that PP-5 tetramers promote membrane depolarization is consistent with the calculated Hill coefficient of 3.725, determined from a Hill analysis of the depolarization data. Copyright (C) 2000 Elsevier Science B.V

A Peptide Analogue to a Fusion Domain Within Photoreceptor Peripherin/rds Promotes Membrane Adhesion and Depolarization

Photoreceptor peripherin/rds promotes membrane fusion, through a putative fusion domain located within the C-terminus (Boesze-Battaglia et al., Biochemistry 37 (1998) 9477-9487). A peptide analogue to this region, PP-5, competitively inhibits peripherin/rds mediated fusion in a cell free assay system. To characterize how this region is involved in the fusion process we investigated two of the individual steps in membrane fusion, membrane adhesion and membrane destabilization inferred from depolarization studies. Membrane depolarization was measured as the collapse of a valinomycin induced K+ diffusion potential in model membranes, using a potential sensitive fluorescent probe, diS-C2-5. PP-5 induced membrane depolarization in a concentration dependent manner. PP-5 has been shown by Fourier transform infrared spectroscopy to be an amphiphilic α-helix. Therefore, the requirement for an amphiphilic α-helix to promote depolarization was tested using two mutant peptides designed to disrupt either the amphiphilic nature of PP-5 (PP-5AB) or the α-helical structure (PP-5HB). PP-5AB inhibited PP-5 induced depolarization when added in an equimolar ratio to PP-5. Neither mutant peptide alone or in combination with PP-5 had any effect on calcium dependent vesicle aggregation. Using non-denaturing gel electrophoresis and size exclusion chromatography techniques PP-5 was shown to form a tetrameric complex. Equimolar mixtures of PP-5 and PP-5AB formed a heterotetramer which was unable to promote membrane depolarization. The hypothesis that PP-5 tetramers promote membrane depolarization is consistent with the calculated Hill coefficient of 3.725, determined from a Hill analysis of the depolarization data. Copyright (C) 2000 Elsevier Science B.V

A Peptide Analogue to a Fusion Domain Within Photoreceptor Peripherin/rds Promotes Membrane Adhesion and Depolarization

Photoreceptor peripherin/rds promotes membrane fusion, through a putative fusion domain located within the C-terminus (Boesze-Battaglia et al., Biochemistry 37 (1998) 9477-9487). A peptide analogue to this region, PP-5, competitively inhibits peripherin/rds mediated fusion in a cell free assay system. To characterize how this region is involved in the fusion process we investigated two of the individual steps in membrane fusion, membrane adhesion and membrane destabilization inferred from depolarization studies. Membrane depolarization was measured as the collapse of a valinomycin induced K+ diffusion potential in model membranes, using a potential sensitive fluorescent probe, diS-C2-5. PP-5 induced membrane depolarization in a concentration dependent manner. PP-5 has been shown by Fourier transform infrared spectroscopy to be an amphiphilic α-helix. Therefore, the requirement for an amphiphilic α-helix to promote depolarization was tested using two mutant peptides designed to disrupt either the amphiphilic nature of PP-5 (PP-5AB) or the α-helical structure (PP-5HB). PP-5AB inhibited PP-5 induced depolarization when added in an equimolar ratio to PP-5. Neither mutant peptide alone or in combination with PP-5 had any effect on calcium dependent vesicle aggregation. Using non-denaturing gel electrophoresis and size exclusion chromatography techniques PP-5 was shown to form a tetrameric complex. Equimolar mixtures of PP-5 and PP-5AB formed a heterotetramer which was unable to promote membrane depolarization. The hypothesis that PP-5 tetramers promote membrane depolarization is consistent with the calculated Hill coefficient of 3.725, determined from a Hill analysis of the depolarization data. Copyright (C) 2000 Elsevier Science B.V

Autorenidentifikation für wissenschaftliche Publikationen. Bericht über den Workshop der DINI-AG Elektronisches Publizieren auf dem 6. Bibliothekskongress

Identifikationssysteme für Autorinnen und Autoren spielen für das wissenschaftliche Publizieren eine zentrale Rolle. Sie erlauben die eindeutige Zuordnung von Publikationen zu ihren Urheberinnen und Urhebern, ermöglichen - auch auf übergreifenden Plattformen - gezielte Rechercheeinstiege und unterstützen die semantische Verknüpfung im Netz. Darüber hinaus können Autorenidentifikationssysteme zur einfachen Pflege von Publikationslisten und für die Forschungsevaluation genutzt werden. Neben zahlreichen proprietären Systemen von Verlagen und Datenbankbetreibern widmet sich im Wissenschaftsbereich die global agierende Initiative ORCID (Open Researcher and Contributer ID) der Vergabe einer eindeutigen ID für Forschende. Im deutschen Bibliothekswesen kommt zur Erschließung mit Personenbezug vor allem der Gemeinsamen Normdatei (GND) entscheidende Bedeutung zu. In den Open-Access-Repositorien deutscher Hochschulen und Forschungseinrichtungen hat sich die Verwendung übergreifender Autorenidentifikationssystemen dagegen bislang kaum durchgesetzt. Im Rahmen des 6. Bibliothekskongresses veranstaltete die AG Elektronisches Publizieren der Deutschen Initiative für Netzwerkinformation (DINI) am 15.03.2016 einen Workshop zu diesem Themenfeld. Die Referentinnen und Referenten haben das Thema Autorenidentifikation und deren Anwendungsszenarien aus unterschiedlichen Blickwinkeln beleuchtet. Der vorliegende Beitrag gibt einen Überblick über die Themen des Workshops

Multicenter EuroTravNet/GeoSentinel Study of Travel-related Infectious Diseases in Europe

We analyzed prospective data on 17,228 European patients who sought treatment at GeoSentinel sites from 1997 to 2007. Gastrointestinal illness (particularly in tourists), fever (those visiting friends and relatives [VFRs]), and skin disorders (in tourists) were the most common reasons for seeking medical care. Diagnoses varied by country of origin, region visited, or categories of travelers. VFRs who returned from sub-Saharan Africa and Indian Ocean islands were more likely to experience falciparum malaria than any other group. Multiple correspondence analysis identified Italian, French, and Swiss VFRs and expatriate travelers to sub-Saharan Africa and Indian Ocean Islands as most likely to exhibit febrile illnesses. German tourists to Southeast and south-central Asia were most likely to seek treatment for acute diarrhea. Non-European travelers (12,663 patients from other industrialized countries) were less likely to acquire certain travel-associated infectious diseases. These results should be considered in the practice of travel medicine and development of health recommendations for European travelers

Novae from isolated white dwarfs as a source of helium for second generation stars in globular clusters

We explore the possible contribution of classical and recurrent novae from isolated white dwarfs accreting from the intracluster medium to the abundances of "second generation" globular cluster stellar populations. We show that under reasonable assumptions the helium abundances of clusters can be enhanced substantially by these novae and argue that novae should be considered as an important, and perhaps even dominant channel in the evolution of the intracluster medium. We also discuss a possible test for whether helium enhancement really is the cause of the multiple main sequences in globular clusters that is independent of the positions of stars in the color-magnitude diagram.Comment: 6 pages, accepted to MNRA

Virulence evolution in response to vaccination: the case of malaria

Invited paper for the journal Vaccine summarising a workshop at Rutgers University in July 2005 on Vaccination and its evolutionary consequencesOne theory of why some pathogens are virulent (i.e. they damage their host) is that they need to extract resources from their host in order to compete for transmission to new hosts, and resource extraction can damage the host. Here we describe our studies in malaria that test this idea. We go on to show that host immunity can exacerbate selection for virulence and therefore that vaccines that reduce pathogen replication may select for more virulent pathogens, eroding the benefits of vaccination and putting the unvaccinated at greater risk. We suggest that in disease contexts where wild-type parasites can be transmitted through vaccinated hosts, evolutionary outcomes need to be considered