Ectoine is a small zwitterionic osmolyte and compatible solute, which interacts with DNA and modi... more Ectoine is a small zwitterionic osmolyte and compatible solute, which interacts with DNA and modifies ultraviolet radiation damage to DNA.
Background: Acute cellular rejection (ACR) is associated with complications after kidney transpla... more Background: Acute cellular rejection (ACR) is associated with complications after kidney transplantation, such as graft dysfunction and graft loss. Early risk assessment is therefore critical for the improvement of transplantation outcomes. In this work, we retrospectively analyzed a pre-transplant HLA antigen bead assay data set that was acquired by the e:KID consortium as part of a systems medicine approach. Results: The data set included single antigen bead (SAB) reactivity profiles of 52 low-risk graft recipients (negative complement dependent cytotoxicity crossmatch, PRA < 30%) who showed detectable pre-transplant anti-HLA 1 antibodies. To assess whether the reactivity profiles provide a means for ACR risk assessment, we established a novel approach which differs from standard approaches in two aspects: the use of quantitative continuous data and the use of a multiparameter classification method. Remarkably, it achieved significant prediction of the 38 graft recipients who experienced ACR with a balanced accuracy of 82.7% (sensitivity = 76.5%, specificity = 88.9%). Conclusions: The resultant classifier achieved one of the highest prediction accuracies in the literature for pre-transplant risk assessment of ACR. Importantly, it can facilitate risk assessment in non-sensitized patients who lack donor-specific antibodies. As the classifier is based on continuous data and includes weak signals, our results emphasize that not only strong but also weak binding interactions of antibodies and HLA 1 antigens contain predictive information.
We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated... more We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane.
... Baum M, Bielau S, Rittner N, Schmid K, Eggelbusch K, Dahms M, Schlauersbach A, Tahedl H, Beie... more ... Baum M, Bielau S, Rittner N, Schmid K, Eggelbusch K, Dahms M, Schlauersbach A, Tahedl H, Beier M, Guimil R, Scheffler M, Hermann C, Funk JM, Wixmerten A, Reb-scher H, Honig M, Andreae C, Buchner D ... Beier M, Stephan A, Hoheisel JD (2001) Hel Chim Acta 84: 2089 ...
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2016
This study aimed at developing a rapid chromatographic assay to monitor phosphorylation sites in ... more This study aimed at developing a rapid chromatographic assay to monitor phosphorylation sites in peptides. For the analysis of nociceptive signal transduction pathways, the detection of phosphorylated proteins/peptides plays a fundamental role. To get further insights in the phosphorylation mechanism of protein kinase C-ε (PKC-ε) and protein kinase A (PKA), potential targets were divided into subsections resulting in peptides that contain only one possible phospho-binding site. The use of high-performance thin-layer chromatography (HPTLC) offers the possibility of a high throughput of samples and the advantage of a quick sample clean-up. A combined strategy of an effect-directed overlay procedure on the TLC plate using specific antibodies (immunostaining, HPTLC-IS) as well as a parallel, direct mass spectrometric methodology by HPTLC-MALDI-TOF-MS was developed. With regard to HPTLC-IS, validation of the data exhibited a lower limit of detection than the traditionally used protein de...
For plasmids derived from bacteriophage λ, the initiation of bidirectional DNA replication from o... more For plasmids derived from bacteriophage λ, the initiation of bidirectional DNA replication from oriλ depends on the stimulation of transcription from the p R promoter by the host replication initiator protein DnaA. Certain Escherichia coli dnaA(ts) mutants cannot be transformed by wild-type λ plasmids even at the temperature permissive to cell growth. This plasmid-host incompatibility appeared to be due to inefficient stimulation of transcription from the p R promoter by the mutant DnaA protein. This paper shows that there is a second mechanism for the incompatibility between λ plasmids and dnaA(ts) hosts, exemplified in this study by the dnaA46 mutant. This is based on the competition between the λ P protein and the host DnaA and DnaC proteins for DnaB helicase. Both mechanisms must be operative for the incompatibility.
Mitogen-activated protein kinase (MAPK) cascades are universal and highly conserved signal transd... more Mitogen-activated protein kinase (MAPK) cascades are universal and highly conserved signal transduction mod- ules in eucaryotes, including plants. These protein phos- phorylation cascades link extracellular stimuli to a wide range of cellular responses. However, the underlying mechanisms are so far unknown as information about phosphorylation substrates of plant MAPKs is lacking. In this study we addressed the challenging task of
Irradiation of immobilized DNA in solution by direct injection of electrons through a membrane. c... more Irradiation of immobilized DNA in solution by direct injection of electrons through a membrane. c DNA damage detected in in-situ by means of fluorescence. c Tuning into the low-energy electron DNA damage mode by changing the electron impact energy.
This review addresses up-to-date applications of Protein Microarrays. Protein Microarrays play a ... more This review addresses up-to-date applications of Protein Microarrays. Protein Microarrays play a significant role in basic research as well as in clinical applications and are applicable in a lot of fields, e.g., DNA, proteins and small molecules. Additionally they are on the way to enter clinics in routine diagnostics. Protein Microarrays can be powerful tools to improve healthcare. An overview of basic characteristics to mediate essential knowledge of this technique is given. To reach this goal, some challenges still have to be addressed. A few applications of Protein Microarrays in a medical context are shown. Finally, an outlook, where the potential of Protein Microarrays is depicted and speculations how the future of Protein Microarrays will look like are made.
Due to insufficient biomarker validation and poor performances in diagnostic assays, the candidat... more Due to insufficient biomarker validation and poor performances in diagnostic assays, the candidate biomarker verification process has to be improved. Multi-analyte immunoassays are the tool of choice for the identification and detailed validation of protein biomarkers in serum. The process of identification and validation of serum biomarkers, as well as their implementation in diagnostic routine requires an application of independent immunoassay platforms with the possibility of high-throughput. This review will focus on three main multi-analyte immunoassay platforms: planar microarrays, multiplex bead systems and, array-based surface plasmon resonance (SPR) chips. Recent developments of each platform will be discussed for application in clinical proteomics, principles, detection methods, and performance strength. The requirements for specific surface functionalization of assay platforms are continuously increasing. The reasons for this increase is the demand for highly sensitive as...
We describe here a systematic approach to the identification of human proteins and protein fragme... more We describe here a systematic approach to the identification of human proteins and protein fragments that can be expressed as soluble proteins in Escherichia coli. A cDNA expression library of 10,825 clones was screened by small-scale expression and purification and 2,746 clones were identified. Sequence and protein-expression data were entered into a public database. A set of 163 clones was selected for structural analysis and 17 proteins were prepared for crystallization, leading to three new structures.
Ectoine is a small zwitterionic osmolyte and compatible solute, which interacts with DNA and modi... more Ectoine is a small zwitterionic osmolyte and compatible solute, which interacts with DNA and modifies ultraviolet radiation damage to DNA.
Background: Acute cellular rejection (ACR) is associated with complications after kidney transpla... more Background: Acute cellular rejection (ACR) is associated with complications after kidney transplantation, such as graft dysfunction and graft loss. Early risk assessment is therefore critical for the improvement of transplantation outcomes. In this work, we retrospectively analyzed a pre-transplant HLA antigen bead assay data set that was acquired by the e:KID consortium as part of a systems medicine approach. Results: The data set included single antigen bead (SAB) reactivity profiles of 52 low-risk graft recipients (negative complement dependent cytotoxicity crossmatch, PRA < 30%) who showed detectable pre-transplant anti-HLA 1 antibodies. To assess whether the reactivity profiles provide a means for ACR risk assessment, we established a novel approach which differs from standard approaches in two aspects: the use of quantitative continuous data and the use of a multiparameter classification method. Remarkably, it achieved significant prediction of the 38 graft recipients who experienced ACR with a balanced accuracy of 82.7% (sensitivity = 76.5%, specificity = 88.9%). Conclusions: The resultant classifier achieved one of the highest prediction accuracies in the literature for pre-transplant risk assessment of ACR. Importantly, it can facilitate risk assessment in non-sensitized patients who lack donor-specific antibodies. As the classifier is based on continuous data and includes weak signals, our results emphasize that not only strong but also weak binding interactions of antibodies and HLA 1 antigens contain predictive information.
We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated... more We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane.
... Baum M, Bielau S, Rittner N, Schmid K, Eggelbusch K, Dahms M, Schlauersbach A, Tahedl H, Beie... more ... Baum M, Bielau S, Rittner N, Schmid K, Eggelbusch K, Dahms M, Schlauersbach A, Tahedl H, Beier M, Guimil R, Scheffler M, Hermann C, Funk JM, Wixmerten A, Reb-scher H, Honig M, Andreae C, Buchner D ... Beier M, Stephan A, Hoheisel JD (2001) Hel Chim Acta 84: 2089 ...
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2016
This study aimed at developing a rapid chromatographic assay to monitor phosphorylation sites in ... more This study aimed at developing a rapid chromatographic assay to monitor phosphorylation sites in peptides. For the analysis of nociceptive signal transduction pathways, the detection of phosphorylated proteins/peptides plays a fundamental role. To get further insights in the phosphorylation mechanism of protein kinase C-ε (PKC-ε) and protein kinase A (PKA), potential targets were divided into subsections resulting in peptides that contain only one possible phospho-binding site. The use of high-performance thin-layer chromatography (HPTLC) offers the possibility of a high throughput of samples and the advantage of a quick sample clean-up. A combined strategy of an effect-directed overlay procedure on the TLC plate using specific antibodies (immunostaining, HPTLC-IS) as well as a parallel, direct mass spectrometric methodology by HPTLC-MALDI-TOF-MS was developed. With regard to HPTLC-IS, validation of the data exhibited a lower limit of detection than the traditionally used protein de...
For plasmids derived from bacteriophage λ, the initiation of bidirectional DNA replication from o... more For plasmids derived from bacteriophage λ, the initiation of bidirectional DNA replication from oriλ depends on the stimulation of transcription from the p R promoter by the host replication initiator protein DnaA. Certain Escherichia coli dnaA(ts) mutants cannot be transformed by wild-type λ plasmids even at the temperature permissive to cell growth. This plasmid-host incompatibility appeared to be due to inefficient stimulation of transcription from the p R promoter by the mutant DnaA protein. This paper shows that there is a second mechanism for the incompatibility between λ plasmids and dnaA(ts) hosts, exemplified in this study by the dnaA46 mutant. This is based on the competition between the λ P protein and the host DnaA and DnaC proteins for DnaB helicase. Both mechanisms must be operative for the incompatibility.
Mitogen-activated protein kinase (MAPK) cascades are universal and highly conserved signal transd... more Mitogen-activated protein kinase (MAPK) cascades are universal and highly conserved signal transduction mod- ules in eucaryotes, including plants. These protein phos- phorylation cascades link extracellular stimuli to a wide range of cellular responses. However, the underlying mechanisms are so far unknown as information about phosphorylation substrates of plant MAPKs is lacking. In this study we addressed the challenging task of
Irradiation of immobilized DNA in solution by direct injection of electrons through a membrane. c... more Irradiation of immobilized DNA in solution by direct injection of electrons through a membrane. c DNA damage detected in in-situ by means of fluorescence. c Tuning into the low-energy electron DNA damage mode by changing the electron impact energy.
This review addresses up-to-date applications of Protein Microarrays. Protein Microarrays play a ... more This review addresses up-to-date applications of Protein Microarrays. Protein Microarrays play a significant role in basic research as well as in clinical applications and are applicable in a lot of fields, e.g., DNA, proteins and small molecules. Additionally they are on the way to enter clinics in routine diagnostics. Protein Microarrays can be powerful tools to improve healthcare. An overview of basic characteristics to mediate essential knowledge of this technique is given. To reach this goal, some challenges still have to be addressed. A few applications of Protein Microarrays in a medical context are shown. Finally, an outlook, where the potential of Protein Microarrays is depicted and speculations how the future of Protein Microarrays will look like are made.
Due to insufficient biomarker validation and poor performances in diagnostic assays, the candidat... more Due to insufficient biomarker validation and poor performances in diagnostic assays, the candidate biomarker verification process has to be improved. Multi-analyte immunoassays are the tool of choice for the identification and detailed validation of protein biomarkers in serum. The process of identification and validation of serum biomarkers, as well as their implementation in diagnostic routine requires an application of independent immunoassay platforms with the possibility of high-throughput. This review will focus on three main multi-analyte immunoassay platforms: planar microarrays, multiplex bead systems and, array-based surface plasmon resonance (SPR) chips. Recent developments of each platform will be discussed for application in clinical proteomics, principles, detection methods, and performance strength. The requirements for specific surface functionalization of assay platforms are continuously increasing. The reasons for this increase is the demand for highly sensitive as...
We describe here a systematic approach to the identification of human proteins and protein fragme... more We describe here a systematic approach to the identification of human proteins and protein fragments that can be expressed as soluble proteins in Escherichia coli. A cDNA expression library of 10,825 clones was screened by small-scale expression and purification and 2,746 clones were identified. Sequence and protein-expression data were entered into a public database. A set of 163 clones was selected for structural analysis and 17 proteins were prepared for crystallization, leading to three new structures.
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Papers by Harald Seitz