Biomedical subjects

Yvonne Wagner

Publications and source records attributed to Yvonne Wagner.

4 recordsLinked to original sources

PubMed2006

Periodontopathogenic bacteria multiply in the environmental amoeba Acanthamoeba castellani.

Porphyromonas gingivalis and Prevotella intermedia are obligate anaerobe gram-negative periodontopathogenic bacteria. Free-living amoebae, such as Acanthamoeba spp., are well known as environmental hosts of several human pathogens, such as Franciscella tularensis, Chlamydia pneumoniae, Legionella pneumophila and Mycobacteria spp. This study tested the ability of P. gingivalis and P. intermedia to become internalized, to survive and replicate in Acanthamoeba castellani. Our results show for the first time that P. gingivalis and P. intermedia isolated from periodontitis patients are capable of infecting A. castellani cells in vitro and are able to survive and multiply intracellularly. From our experimental data it can be suggested that periodontopathogenic bacteria might be conditioned in the evolution by amoebae and free-living amoebae can act as an environmental reservoir for these pathogens.

Acanthamoeba castellanii↗

PubMed2004

Challenges in mass spectrometry-based proteomics.

During the last decade, protein analysis and proteomics have been established as new tools for understanding various biological problems. As the identification of proteins after classical separation techniques, such as two-dimensional gel electrophoresis, have become standard methods, new challenges arise in the field of proteomics. The development of "functional proteomics" combines functional characterization, like regulation, localization and modification, with the identification of proteins for deeper insight into cellular functions. Therefore, different mass spectrometric techniques for the analysis of post-translational modifications, such as phosphorylation and glycosylation, have been established as well as isolation and separation methods for the analysis of highly complex samples, e.g. protein complexes or cell organelles. Furthermore, quantification of protein levels within cells is becoming a focus of interest as mass spectrometric methods for relative or even absolute quantification have currently not been available. Protein or genome databases have been an essential part of protein identification up to now. Thus, de novo sequencing offers new possibilities in protein analytical studies of organisms not yet completely sequenced. The intention of this review is to provide a short overview about the current capabilities of protein analysis when addressing various biological problems.

Algorithms↗

PubMed2003

The proteome of Saccharomyces cerevisiae mitochondria.

We performed a comprehensive approach to determine the proteome of Saccharomyces cerevisiae mitochondria. The proteins of highly pure yeast mitochondria were separated by several independent methods and analyzed by tandem MS. From >20 million MS spectra, 750 different proteins were identified, indicating an involvement of mitochondria in numerous cellular processes. All known components of the oxidative phosphorylation machinery, the tricarboxylic acid cycle, and the stable mitochondria-encoded proteins were found. Based on the mitochondrial proteins described in the literature so far, we calculate that the identified proteins represent approximately 90% of all mitochondrial proteins. The function of a quarter of the identified proteins is unknown. The mitochondrial proteome will provide an important database for the analysis of new mitochondrial and mitochondria-associated functions and the characterization of mitochondrial diseases.

Citric Acid Cycle↗

PubMed2003

Multidimensional nano-HPLC for analysis of protein complexes.

The analysis of macromolecular protein complexes is an important factor in understanding most cellular processes, e.g., protein transport into cell organells, signal transduction via biological membranes, apoptosis, energy metabolism, directed motion of cells, and cell division. These complexes are not only built of various numbers of different proteins but also of prosthetic groups and RNA molecules. To understand the role each protein plays in a complex, a complete analysis of all protein compounds is necessary. Therefore, several separation steps have to be coupled to mass spectrometry to identify the proteins. In this work, we describe the application of multidimensional liquid chromatography, SCX-RP-LC as well as SAX-RP-LC, coupled to electrospray ion trap mass spectrometry. Tryptic digested ribosomes were separated by ion exchange chromatography manually collected and prepared for reversed phase chromatography to analyze the peptides via nano-ESI mass spectrometry. The total numbers of identified proteins are compared in consideration of the separation method (SCX-RP versus SAX-RP).

Amino Acid Sequence↗