Das Jahrbuch der Heinrich-Heine-Universität Düsseldorf versteht sich als Forum für den wissenschaftlichen Dialog der Universität zu Zeitfragen, zu aktuellen Problemlagen und Herausforderungen von Wissenschaft und Gesellschaft, als Brücke der Vermittlung zwischen Forschung und Öffentlichkeit sowie als Gedächtnisort der Innovationen und des Fortschritts in Forschung und Lehre der Universität und als Speicher der wissenschafts- und hochschulpolitischen Entscheidungen für strukturelle Weichenstellungen mit Langzeitwirkung. Zielgruppe ist die an den Arbeitsergebnissen in Forschung und Lehre sowie an wissenschaftlichen Entscheidungen der Heinrich-Heine-Universität interessierte Öffentlichkeit. Diese soll über die Dynamik und das sich wandelnde Profil der Fakultäten kontinuierlich informiert und in die Lage versetzt werden, sich intensiver mit neuen Forschungsfragen und -ergebnissen auseinander zu setzen. Es geht vor allem darum, die Bedeutung der Forschung für die verschiedenen Lebensbereiche und damit auch für unsere gesellschaftliche Entwicklung bewusst zu machen. Die Beiträge vermitteln gleichsam als Momentaufnahme einen Ausschnitt aus dem permanenten Prozess des sich verändernden Profils der Fakultäten. Erst eine Folge von Jahrbüchern eröffnet die Chance, die Tiefe des Gesamtprofils auszuloten und dessen Nachhaltigkeit zu erkennen.

Die NRW-Forschungsschule BioStruct – Neue Wege interdisziplinärer Graduiertenausbildung an der Heinrich-Heine-Universität Düsseldorf was published in Jahrbuch der Heinrich-Heine-Universität Düsseldorf 2007/2008 on page 555.

Shaping the Future of Doctoral Training: iGRAD – Interdisciplinary Graduate and Research Academy Düsseldorf was published in Neues aus Wissenschaft und Lehre der Heinrich-Heine-Universität Düsseldorf 2010 on page 671.

Reducing sugars and reactive dicarbonyl compounds play a major role in glycation of proteins in vivo. Glycation of proteins is the first step in of a nonenzymatic reaction, resulting in advanced glycation end products (AGEs). AGEs can inactivate proteins or modify their biological activities. Therefore, it is important to understand the mechanism of AGE formation. Here, we systematically analyzed the kinetics of AGE formation in vitro by fluorescence and absorption measurements utilizing a microplate reader system and bovine serum albumin (BSA) as a model protein. Comparing different concentrations of BSA, we applied various reducing sugars and reactive dicarbonyl compounds as AGE-inducing agents at different concentrations. In summary, this experimental setup enabled us to measure the kinetics of AGE formation in an efficient and defined way.

Prion diseases are fatal neurodegenerative diseases that occur either spontaneously or genetically or are caused by infection. Spontaneously occuring prion diseases are age related. The infectious agents, called prions, are proteinaceous infectious particles, composed mainly of the host-encoded prion protein (PrP) in a misfolded, insoluble, and aggregated isoform. Advanced glycation end products (AGEs) are well known to contribute to protein misfolding, insolubility, and aggregation. Thus, we studied if AGE-modification could influence PrP aggregation. We analyzed PrP preparations immunochemically to determine if they contain AGE-modified PrP. We also studied the influence of AGE modifications on the PrP aggregation process in vitro.

The conversion of the cellular isoform of the prion protein into the pathogenic isoform PrP(Sc) is the key event in prion diseases. The disease can occur spontaneously genetically or by infection. In earlier studies we presented an in vitro conversion system which simulates the structural transition in recPrP by varying low concentrations of SDS at constant NaCl. In the present study we adopted the conversion system from experimental Scrapie in hamster to bovine recPrP and generated amyloid fibrils. The intermediate state which is optimal for fibril formation is a soluble, beta-rich state. The system was extended using BSE-prions as seeds and led to an acceleration of fibril formation by orders of magnitude. This seeded amyloid formation assay avoids any PK-treatment, is therefore able to detect even PK-sensitive PrP(Sc) and does not require cellular components.

Prion diseases like Creutzfeldt-jakob disease in humans or scrapie in sheep and goats are infectious neurodegenerative diseases. Their infectious agent, called prion, is composed mainly of aggregated and misfolded prion protein and non-proteinaceous components. An example of such a common non-proteinaceous secondary component of natural prions is the polysaccharide scaffold. We studied the influence of such a polysaccharide on the conformational transition of PrP applying an in vitro conversion system. Here we report that glycogen supports and accelerates PrP amorphous aggregation similar to seeded aggregation and leads to co-aggregates. Furthermore, PrP fibril formation was highly accelerated in the presence of glycogen.

A characteristic feature of prion diseases such as bovine spongiform encephalopathy (BSE) is the accumulation of a pathological isoform of the host-encoded prion protein, PrP. In contrast to its cellular isoform PrPC, the pathological isoform PrPSc forms insoluble aggregates. All commercial BSE tests currently used for routine testing are based on the proteinase K (PK) resistance of PrP, but not all pathological PrP is PK-resistant. In the present study, single prion particles were counted by fluorescence correlation spectroscopy (FCS). The property of PK resistance is not required, i.e., both the PK-resistant and the PK-sensitive parts of the prion particles are detectable. PrP aggregates were prepared from the brains of BSE-infected cattle, as well as from scrapie-infected hamsters, by the NaPTA precipitation method without PK digestion. They were labeled using two different PrP-specific antibodies for FCS measurements in the dual-color mode (2D-FIDA). Within the limited number of samples tested, BSE-infected cattle and scrapie-infected hamsters in the clinical stage of the disease could be distinguished with 100% specificity from a control group. Thus, a diagnostic tool for BSE detection with complete avoidance of PK treatment is presented, which should have particular advantages for testing animals in the preclinical stage.

An inert polysaccharide scaffold identified as a 5-15% component of prion rods (PrP 27-30) is unambiguously distinguishable from the N-glycosyl groups and the GPI anchor of PrP, and consists predominantly of 1,4-linked glucose with some branching via 1,4,6-linked glucose. We show that this polysaccharide scaffold is a common secondary component of prions found in hamster full-length PrP(Sc), prion rods and in mouse ScN2a prions from cell culture. The preparation from prion rods was improved, resulting in a polysaccharide scaffold free of remaining infectivity. Furthermore, we determined the stereochemistry of the glycoside linkages as pre-dominantly if not entirely alpha-glycosidic. The origin of the polysaccharide, its interaction with PrP and its potential relation to glycogen and corpora amylacea are discussed.

Prionkrankheiten sind übertragbare, tödlich verlaufende Erkrankungen des Nervensystems bei Mensch und Tier. Die Natur des Erregers blieb über mehr als 200 Jahre rätselhaft. Im Jahr 1982 wurde von Stanley B. Prusiner die Hypothese aufgestellt, dass der Erreger ein proteinartiges Partikel sei und keine Erbsubstanz besitze. Damit wurde eine neuartige Form von Krankheitserreger postuliert, die so genannten Prionen. Da diese einem zentralen Dogma der Biologie widersprachen, wonach Vermehrung nur mithilfe von Erbsubstanz möglich sei, erregte das Prionenmodell viel Widerspruch. Weltweit wurden Forschungsergebnisse zusammengetragen, die das Prionenmodell stützten, der endgültige Beweis gelang jedoch erst 2004, als man synthetische Prionen herstellen und damit im Reagenzglas Infektiosität erzeugen konnte. So wurde das 1997 mit dem Nobelpreis gewürdigte Prionenmodell zweifelsfrei bewiesen.

A polysaccharide consisting of mainly 1,4-linked glucose units was found associated with prion rods, which are composed mainly of insoluble aggregates of the N-terminally truncated prion protein (PrP 27-30) exhibiting the ultrastructural and tinctorial properties of amyloid. The polysaccharide differs in composition from the Asn-linked oligosaccharides and the GPI-anchor of the prion protein. Prion rods were prepared from scrapie-infected hamster brains using two different purification protocols. Prolonged digestion of rods with proteinase K reduced PrP by a factor of at least 500, leaving about 10% (w/w) of the sample as an insoluble remnant. Only glucose was obtained by acid hydrolysis of the remnant and methylation analysis showed 80% 1,4-, 15% 1,6- and 5% 1,4,6-linked glucose units. The physical and chemical properties as well as the absence of terminal glucose units indicate a very high molecular mass of the polysaccharide. No evidence was found for covalent bonds between PrP and the polysaccharide. The polysaccharide certainly contributes to the unusual chemical and physical stability of prion rods, acting like a scaffold. A potential structural and/or functional relevance of the polysaccharide scaffold is discussed.