Publications by authors named "Bernhard Ay"

Proteasomes are cellular proteases involved in the degradation of numerous cellular proteins. The 20S proteasome is a cylindrical 28-mer protein complex composed of two outer heptameric α-rings forming the entrance for the protein substrate and two inner heptameric β-rings carrying the catalytic sites. Numerous in vitro studies have provided evidence that the 20S proteasome may degrade peptides of various lengths and even unfolded full-length polypeptide chains.

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The malaria parasite invades the terminally differentiated erythrocytes, where it grows and multiplies surrounded by a parasitophorous vacuole. Plasmodium blood stages translocate newly synthesized proteins outside the parasitophorous vacuole and direct them to various erythrocyte compartments, including the cytoskeleton and the plasma membrane. Here, we show that the remodeling of the host cell directed by the parasite also includes the recruitment of dematin, an actin-binding protein of the erythrocyte membrane skeleton and its repositioning to the parasite.

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Celery is a frequent cause of food allergy in pollen-sensitized patients and can induce severe allergic reactions. Clinical symptoms cannot be predicted by skin prick tests (SPTs) or by determining allergen-specific immunoglobulin E (IgE). Our aim was to identify specific IgE binding peptides by using an array technique.

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Development of array technologies started in the late 1980s and was first extensively applied to DNA arrays especially in the genomic field. Today this technique has become a powerful tool for high-throughput approaches in biology and chemistry. Progresses were mainly driven by the human genome project and were associated with the development of several new technologies, which led to the onset of additional "omic" topics like proteomics, glycomics, antibodyomics or lipidomics.

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A high demand of interest concerning binding assays to study the consequences of posttranscriptional phosphorylation may be addressed by peptide array-based methods. A crucial factor for de novo chemical approaches to generate such arrays is the possibility to rationally permutate phosphorylation events along a huge number of sequences. The simple principle behind this advantage is the stepwise synthesis of peptides, which allows the incorporation of either phosphorylated or nonphosphorylated derivates at serine, threonine, and tyrosine positions.

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The SPOT technology can fulfill most requirements for highly parallel, multiple peptide synthesis of soluble peptides within the upper microgram range. Here, we report on an improved method using hydroxymethylphenoxyacetic acid (HMPA) for 19 amino acids and 4-(4-hydroxymethyl-3-methoxyphenoxy)-butyric acid (HMPB) for proline as acidic labile linkers in SPOT synthesis. Using this approach we could reduce side-chain reactions normally occurring during conventional alkaline peptide cleavage from cellulose membranes.

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Background: Parvovirus B19 (B19V) is the most commonly detected virus in endomyocardial biopsies (EMBs) from patients with inflammatory cardiomyopathy (DCMi). Despite the importance of T-cells in antiviral defense, little is known about the role of B19V specific T-cells in this entity.

Methodology And Principal Findings: An exceptionally high B19V viral load in EMBs (115,091 viral copies/mug nucleic acids), peripheral blood mononuclear cells (PBMCs) and serum was measured in a DCMi patient at initial presentation, suggesting B19V viremia.

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Transient macromolecular complexes are often formed by protein-protein interaction domains (e.g., PDZ, SH2, SH3, WW), which are often regulated (positively or negatively) by phosphorylation.

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Little about the reliability of measurements obtained using synthetic peptide microarrays is known. We report results from a study on the quantitative reliability of microarrays manufactured by robot-supported immobilization of presynthesized peptides for different microarray platforms. Technological precision is assessed for inter- and intra-device readout comparisons.

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Human cytomegalovirus (CMV) is a major cause of morbidity in immunocompromised individuals. However, no efficient vaccine has been developed to date. Identification of T-cell target proteins and epitopes is crucial not only for developing a successful immunization strategy, but also for new approaches using adoptive transfer of antigen-specific T-cells.

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The analysis of T-cell responses to peptides has recently become a busy area of immunologic research. Peptides may be used as single stimulants, pools or libraries, or as part of peptide/major histocompatibility complexes (MHC) for direct T-cell receptor staining. For stimulating T cells, peptides must be bound to MHC molecules.

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SPOT synthesis permits parallel synthesis and screening of thousands of cellulose membrane-bound peptides to study protein-protein interactions in a proteomic context. Recognition of C-terminal residues is one of the most common binding features of PDZ domains. Unfortunately, most solid support-bound peptide libraries lack a free C terminus due to C-terminal fixation on the solid support.

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