Entwicklung und Charakterisierung von Komplexen aus Cetrorelix und biophilen Trägermaterialien

Die Dissertation beschreibt Arbeiten zur Herstellung neuer Cetrorelixkomplexe, zur Kinetik der dynamischen Liberation, zur Struktur von Aggregaten und Komplexen von Cetrorelix und zur Berechnung von Komplexeigenschaften mit Molecular Modeling.Presented are results about new complexes of cetrorelix, the kinetics of dynamical liberations, the structure of Cetrorelix aggregates and complexes and the computation of properties of complexes by molecular modeling

The evolutionary dynamics of protein-protein interaction networks inferred from the reconstruction of ancient networks

Cellular functions are based on the complex interplay of proteins, therefore the structure and dynamics of these protein-protein interaction (PPI) networks are the key to the functional understanding of cells. In the last years, large-scale PPI networks of several model organisms were investigated. Methodological improvements now allow the analysis of PPI networks of multiple organisms simultaneously as well as the direct modeling of ancestral networks. This provides the opportunity to challenge existing assumptions on network evolution. We utilized present-day PPI networks from integrated datasets of seven model organisms and developed a theoretical and bioinformatic framework for studying the evolutionary dynamics of PPI networks. A novel filtering approach using percolation analysis was developed to remove low confidence interactions based on topological constraints. We then reconstructed the ancient PPI networks of different ancestors, for which the ancestral proteomes, as well as the ancestral interactions, were inferred. Ancestral proteins were reconstructed using orthologous groups on different evolutionary levels. A stochastic approach, using the duplication-divergence model, was developed for estimating the probabilities of ancient interactions from today's PPI networks. The growth rates for nodes, edges, sizes and modularities of the networks indicate multiplicative growth and are consistent with the results from independent static analysis. Our results support the duplication-divergence model of evolution and indicate fractality and multiplicative growth as general properties of the PPI network structure and dynamics

Hybrid de novo transcriptome assembly of poinsettia (Euphorbia pulcherrima Willd. Ex Klotsch) bracts

Background Poinsettia is a popular and important ornamental crop, mostly during the Christmas season. Its bract coloration ranges from pink/red to creamy/white shades. Despite its ornamental value, there is a lack of knowledge about the genetics and molecular biology of poinsettia, especially on the mechanisms of color formation. We performed an RNA-Seq analysis in order to shed light on the transcriptome of poinsettia bracts. Moreover, we analyzed the transcriptome differences of red- and white-bracted poinsettia varieties during bract development and coloration. For the assembly of a bract transcriptome, two paired-end cDNA libraries from a red and white poinsettia pair were sequenced with the Illumina technology, and one library from a red-bracted variety was used for PacBio sequencing. Both short and long reads were assembled using a hybrid de novo strategy. Samples of red- and white-bracted poinsettias were sequenced and comparatively analyzed in three color developmental stages in order to understand the mechanisms of color formation and accumulation in the species. Results The final transcriptome contains 288,524 contigs, with 33% showing confident protein annotation against the TAIR10 database. The BUSCO pipeline, which is based on near-universal orthologous gene groups, was applied to assess the transcriptome completeness. From a total of 1440 BUSCO groups searched, 77% were categorized as complete (41% as single-copy and 36% as duplicated), 10% as fragmented and 13% as missing BUSCOs. The gene expression comparison between red and white varieties of poinsettia showed a differential regulation of the flavonoid biosynthesis pathway only at particular stages of bract development. An initial impairment of the flavonoid pathway early in the color accumulation process for the white poinsettia variety was observed, but these differences were no longer present in the subsequent stages of bract development. Nonetheless, GSTF11 and UGT79B10 showed a lower expression in the last stage of bract development for the white variety and, therefore, are potential candidates for further studies on poinsettia coloration. Conclusions In summary, this transcriptome analysis provides a valuable foundation for further studies on poinsettia, such as plant breeding and genetics, and highlights crucial information on the molecular mechanism of color formation

Comprehensive in silico prediction and analysis of chlamydial outer membrane proteins reflects evolution and life style of the Chlamydiae

<p>Abstract</p> <p>Background</p> <p>Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial outer membrane proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic <it>in silico </it>approach, including the calculation of clusters of orthologues, to predict outer membrane proteins using conservative criteria. We tested this approach using <it>Escherichia coli </it>(positive control) and <it>Bacillus subtilis </it>(negative control), and applied it to five chlamydial species; <it>Chlamydia trachomatis</it>, <it>Chlamydia muridarum</it>, <it>Chlamydia </it>(a.k.a. <it>Chlamydophila</it>) <it>pneumoniae</it>, <it>Chlamydia </it>(a.k.a. <it>Chlamydophila</it>) <it>caviae</it>, and <it>Protochlamydia amoebophila</it>.</p> <p>Results</p> <p>In total, 312 chlamydial outer membrane proteins and lipoproteins in 88 orthologous clusters were identified, including 238 proteins not previously recognized to be located in the outer membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among <it>Chlamydiae</it>, <it>Verrucomicrobia</it>, <it>Lentisphaerae </it>and <it>Planctomycetes </it>as well as lifestyle-dependent conservation of the chlamydial outer membrane protein composition.</p> <p>Conclusion</p> <p>This analysis suggested a correlation between the outer membrane protein composition and the host range of chlamydiae and revealed a common set of outer membrane proteins shared by these intracellular bacteria. The collection of predicted chlamydial outer membrane proteins is available at the online database pCOMP <url>http://www.microbial-ecology.net/pcomp</url> and might provide future guidance in the quest for anti-chlamydial vaccines.</p

SIMAP: the similarity matrix of proteins

Similarity Matrix of Proteins (SIMAP) () provides a database based on a pre-computed similarity matrix covering the similarity space formed by >4 million amino acid sequences from public databases and completely sequenced genomes. The database is capable of handling very large datasets and is updated incrementally. For sequence similarity searches and pairwise alignments, we implemented a grid-enabled software system, which is based on FASTA heuristics and the Smith–Waterman algorithm. Our ProtInfo system allows querying by protein sequences covered by the SIMAP dataset as well as by fragments of these sequences, highly similar sequences and title words. Each sequence in the database is supplemented with pre-calculated features generated by detailed sequence analyses. By providing WWW interfaces as well as web-services, we offer the SIMAP resource as an efficient and comprehensive tool for sequence similarity searches

Cloning and characterization of Enterobacter sakazakii pigment genes and in situ spectroscopic analysis of the pigment

Enterobacter sakazakii is considered an opportunistic foodborne pathogen that is characterized by formation of yellow-pigmented colonies. Because of the lack of basic knowledge about Enterobacter sakazakii genetics, the BAC approach and the heterologous expression of the pigment in Escherichia coli were used to elucidate the molecular structure of the genes responsible for pigment production in Enterobacter sakazakii strain ES5. Sequencing and annotation of a 33.025 bp fragment revealed seven ORFs that could be assigned to the carotenoid biosynthesis pathway. The gene cluster had the organization crtE-idi-XYIBZ, with the crtE-idi-XYIB genes putatively transcribed as an operon and the crtZ gene transcribed in the opposite orientation. The carotenogenic nature of the pigment of Enterobacter sakazakii wt was ascertained by in situ analysis using visible microspectroscopy and resonance Raman microspectroscop

SIMAP--the database of all-against-all protein sequence similarities and annotations with new interfaces and increased coverage

The Similarity Matrix of Proteins (SIMAP, http://mips.gsf.de/simap/) database has been designed to massively accelerate computationally expensive protein sequence analysis tasks in bioinformatics. It provides pre-calculated sequence similarities interconnecting the entire known protein sequence universe, complemented by pre-calculated protein features and domains, similarity clusters and functional annotations. SIMAP covers all major public protein databases as well as many consistently re-annotated metagenomes from different repositories. As of September 2013, SIMAP contains >163 million proteins corresponding to ∼70 million non-redundant sequences. SIMAP uses the sensitive FASTA search heuristics, the Smith–Waterman alignment algorithm, the InterPro database of protein domain models and the BLAST2GO functional annotation algorithm. SIMAP assists biologists by facilitating the interactive exploration of the protein sequence universe. Web-Service and DAS interfaces allow connecting SIMAP with any other bioinformatic tool and resource. All-against-all protein sequence similarity matrices of project-specific protein collections are generated on request. Recent improvements allow SIMAP to cover the rapidly growing sequenced protein sequence universe. New Web-Service interfaces enhance the connectivity of SIMAP. Novel tools for interactive extraction of protein similarity networks have been added. Open access to SIMAP is provided through the web portal; the portal also contains instructions and links for software access and flat file downloads

EffectiveDB--updates and novel features for a better annotation of bacterial secreted proteins and Type III, IV, VI secretion systems

Protein secretion systems play a key role in the interaction of bacteria and hosts. EffectiveDB (http://effectivedb.org) contains pre-calculated predictions of bacterial secreted proteins and of intact secretion systems. Here we describe a major update of the database, which was previously featured in the NAR Database Issue. EffectiveDB bundles various tools to recognize Type III secretion signals, conserved binding sites of Type III chaperones, Type IV secretion peptides, eukaryotic-like domains and subcellular targeting signals in the host. Beyond the analysis of arbitrary protein sequence collections, the new release of EffectiveDB also provides a ‘genome-mode’, in which protein sequences from nearly complete genomes or metagenomic bins can be screened for the presence of three important secretion systems (Type III, IV, VI). EffectiveDB contains pre-calculated predictions for currently 1677 bacterial genomes from the EggNOG 4.0 database and for additional bacterial genomes from NCBI RefSeq. The new, user-friendly and informative web portal offers a submission tool for running the EffectiveDB prediction tools on user-provided data

Genetic diversity of the obligate intracellular bacterium Chlamydophila pneumoniae by genome-wide analysis of single nucleotide polymorphisms: evidence for highly clonal population structure

<p>Abstract</p> <p>Background</p> <p><it>Chlamydophila pneumoniae </it>is an obligate intracellular bacterium that replicates in a biphasic life cycle within eukaryotic host cells. Four published genomes revealed an identity of > 99 %. This remarkable finding raised questions about the existence of distinguishable genotypes in correlation with geographical and anatomical origin.</p> <p>Results</p> <p>We studied the genetic diversity of <it>C. pneumoniae </it>by analysing synonymous single nucleotide polymorphisms (sSNPs) that are under reduced selection pressure. We conducted an in silico analysis of the four sequenced genomes, chose 232 representative sSNPs and analysed the loci in 38 <it>C. pneumoniae </it>isolates. We identified 15 different genotypes that were separated in four major clusters. Clusters were not associated with anatomical or geographical origin. However, animal lineages are basal on the <it>C. pneumomiae </it>phylogeny, suggesting a recent transmission to humans through successive bottlenecks some 150,000 years ago. A lack of detectable variation in 17 isolates emphasizes the extraordinary genetic conservation of this species and the high clonality of the population. Moreover, the largest cluster, which encompasses 80% of all analysed strains, is an extremely young clade, that went through an important population expansion some 3,300 years ago.</p> <p>Conclusion</p> <p>sSNPs have proven useful as a sensitive marker to gain new insights into genetic diversity, population structure and evolutionary history of <it>C. pneumoniae</it>.</p