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Dive into the research topics where Christian Scheler is active.

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Featured researches published by Christian Scheler.


Electrophoresis | 1999

Comparison of two-dimensional electrophoresis patterns of heat shock protein Hsp27 species in normal and cardiomyopathic hearts

Christian Scheler; Xin-Ping Li; Johann Salnikow; Michael J. Dunn; Peter R. Jungblut

Heat shock protein Hsp27 occurs in a complex pattern in human myocardial tissue. Normal and failing explanted human heart from patients with dilated cardiomyopathy (DCM) or ischemic heart failure (IHF), respectively, were analyzed by high resolution two‐dimensional electrophoresis (23×30 cm) and Hsp27 immunostaining. Twelve Hsp27 spots in DCM samples were significantly altered in intensity and ten of these were significantly changed in IHF. Four spots (h1, h2, h4, h5) in DCM samples and three spots (h2, h4, h5) in IHF at a molecular mass of 28 kDa were decreased in intensity. In this study, investigating left ventricles of human myocardium, spot h4 was only detected in normal heart samples. On the other hand, spots with a lower molecular mass of 27 kDa (h14, h15, h17, h20, h21) and 22—23 kDa (46, h47, h50) increased in intensity in failing hearts, suggesting that some form of Hsp27 degradation occurs during heart failure.


Electrophoresis | 1999

A two-dimensional electrophoresis database of rat heart proteins.

Xin Ping Li; Klaus-Peter Pleißner; Christian Scheler; Vera Regitz-Zagrosek; Johann Salnikow; Peter R. Jungblut

More than 3000 myocardial protein species of Wistar Kyoto rat, an important animal model, were separated by high‐resolution two‐dimensional gel electrophoresis (2‐DE) and characterized in terms of isoelectric point (pI) and molecular mass (Mr). Currently, the 2‐DE database contains 64 identified proteins; forty‐three were identified by peptide mass fingerprinting (PMF) using matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS), nine by exclusive comparison with other 2‐DE heart protein databases, and in only 12 cases of 60 attempts N‐terminal sequencing was successful. We used the Make2ddb software package downloaded from the ExPASy server for the construction of a rat myocardial 2‐DE database. The Make2ddb package simplifies the creation of a new 2‐DE database if the Melanie II software and a Sun workstation under Solaris are available. Our 2‐DE database of rat heart proteins can be accessed at URL http://gelmatching.inf.fu‐berlin.de/˜pleiss/2d.


Proteomics | 2002

An iterative calibration method with prediction of post-translational modifications for the construction of a two-dimensional electrophoresis database of mouse mammary gland proteins.

Sevil Aksu; Christian Scheler; Nicole Focks; Fraucke Leenders; Franz Theuring; Johann Salnikow; Peter R. Jungblut

Protein databases serve as general reference recources providing an orientation on two‐dimensional electrophoresis (2‐DE) patterns of interest. The intention behind constructing a 2‐DE database of the water soluble proteins from wild‐type mouse mammary gland tissue was to create a reference before going on to investigate cancer‐associated protein variations. This database shall be deemed to be a model system for mouse tissue, which is open for transgenic or knockout experiments. Proteins were separated and characterized in terms of their molecular weight (Mr) and isoelectric point (pI) by high resolution 2‐DE. The proteins were identified using prevalent proteomics methods. One method was peptide mass fingerprinting by matrix‐assisted laser desorption/ionization‐mass spectrometry. Another method was N‐terminal sequencing by Edman degradation. By N‐terminal sequencing Mr and pI values were specified more accurately and so the calibration of the master gel was obtained more systematically and exactly. This permits the prediction of possible post‐translational modifications of some proteins. The mouse mammary gland 2‐DE protein database created presently contains 66 identified protein spots, which are clickable on the gel pattern. This relational database is accessible on the WWW under the URL: http://www.mpiib‐berlin.mpg.de/2D‐PAGE.


Journal of Analytical Atomic Spectrometry | 2014

Development of a calibration and standardization procedure for LA-ICP-MS using a conventional ink-jet printer for quantification of proteins in electro- and Western-blot assays

Simone Hoesl; Boris Neumann; Sandra Techritz; Michael W. Linscheid; Franz Theuring; Christian Scheler; Norbert Jakubowski; Larissa Mueller

We developed new procedures for internal standardization and calibration to be used for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for elemental micro mapping imaging of biological samples like Western blot membranes and tissue sections. These procedures are based on printing of metal spiked inks onto the top of thin layer samples for simultaneous internal standardization and calibration of LA-ICP-MS. In the case of internal standardization the ink is spiked with indium as an internal standard and homogenously printed over the entire membrane (size 56 cm2) prior to LA-ICP-MS detection, a standard deviation (RSD) value of 2% was achieved. In the second approach the metal content of lanthanide tagged proteins and antibodies after biological work flows was quantified by LA-ICP-MS on nitro-cellulose membranes. In this case the inks spiked with varying metals were printed with different densities on the same nitrocellulose membranes in well-defined squares to produce matrix-matched calibration standards. For validation and calibration the ink squares were excised and the specific metal content was measured by liquid ICP-MS after solubilization of the membrane slice. For the printed calibration standard limits of detection (LOD) of <4 fmol for different metals and relative process standard deviations of 1–2% only were determined via LA-ICP-MS.


Proteomics | 2011

Dietary phytoestrogen supplementation induces sex differences in the myocardial protein pattern of mice: A comparative proteomics study

Karima Schwab; Boris Neumann; Nicolas Vignon-Zellweger; Andreas Fischer; Robert Stein; Peter R. Jungblut; Christian Scheler; Franz Theuring

Elevated cardiovascular risk in postmenopausal women and beneficial actions of estrogen replacement in animal models have been related to protective effects of estrogens. However, randomized trials of hormone replacement therapy with synthetic estrogens in humans failed confirmation and phytoestrogens, natural plant hormones with agonistic properties for estrogen receptors, could represent potential alternatives. The aim of the present study is to characterize an animal model for alternative hormone replacement with genistein as a natural estrogenic compound. We performed a 2‐DE/ESI‐LC‐MS approach in order to identify protein species varying with genistein receipt and sex in their relative abundance in the healthy murine heart (http://www.mpiib‐berlin.mpg.de/2D‐PAGE). Oral genistein treatment revealed a substantial effect on the relative abundance of both estrogen receptors. Several enzymes of the fatty acid metabolism and their transcriptional regulators varied differentially in male and in female animals, at the transcript and/or the protein species level. Increased levels of enzyme species involved in the oxidative phosphorylation and generation of ROS were accompanied by decreased amounts of antioxidants in male mice receiving genistein compared with control males, which have been previously associated with various pathological conditions. Exposure of female animals to genistein provoked an increased abundance of two species of LIM domain‐binding protein and one species of desmin. These proteins have been associated with cardiac hypertrophy and our data warrant caution for the use of them as molecular markers, since the animals did not exhibit any histological signs of cardiac hypertrophy.


Amino Acids | 2011

Adaptation of proteomic techniques for the identification and characterization of protein species from murine heart

Karima Schwab; Boris Neumann; Christian Scheler; Peter R. Jungblut; Franz Theuring

Disturbed energy metabolism with impaired fatty acid oxidation, ATP synthesis and changing levels of contractile proteins has been observed during the development and manifestation of cardiovascular diseases, with the latter showing sexual differences in terms of onset, manifestation and progress. Estrogenic compounds, such as estrogens and phytoestrogens, are known to exert beneficial effects on several cardiovascular parameters. However, global studies implying the normal, non-failing myocardium are rare. Thus, identifying and characterizing protein patterns involved in the maintenance of normal heart physiology at the protein species level will help understanding disease conditions. In this study, we performed an adapted 2-DE/MS approach in order to identify and characterize post-translational modified and truncated protein species from murine heart. Female and male animals of different age were receiving the phytoestrogen genistein and comparative analyses were performed to identify sex and genistein treatment-related effects. Selected 2-DE spots that exposed varying abundance between animal groups and identified as identical proteins were subject to multi-protease cleavage to generate an elevated sequence coverage enabling characterization of post-translational modifications and truncation loci via high-resolution MS. Several truncated, phosphorylated and acetylated species were identified for mitochondrial ATP synthase, malate dehydrogenase and trifunctional enzyme subunit alpha. However, confirmation of several of these modifications by manual spectra interpretation failed. Thus, our results warrant caution for the blind trust in software output. For the regulatory light chain of myosin, we identified an N-terminal processed species, which so far has been related to ischemic conditions only. We tried to unravel the information content of protein species separated by high-resolution 2-DE as an alternative to high-throughput proteomics, which mainly is interested in lists of protein names, ignoring the protein species identity.


Electrophoresis | 2012

Dietary genistein enhances phosphorylation of regulatory myosin light chain in the myocardium of ovariectomized mice

Karima Schwab; Robert Stein; Christian Scheler; Franz Theuring

There is evidence that isoflavones, such as genistein, can directly or indirectly improve lipid profile and lower blood pressure and hence exert cardiovascular protection. It is further believed, that genistein attenuates vascular contraction and thus vascular tone and blood pressure through altering the phosphorylation of the regulatory myosin light chain (MLC) probably via the myosin light chain kinase (MLCK) or the RhoA pathway. However, the direct role of genistein in the myocardium is poorly reviewed. In this study, we investigated the impact of genistein on the cardiac proteome in ovariectomized female mice using a 2DE‐MS approach. Dietary genistein intake considerably changed the abundance of several cytoskeletal and contractile proteins and enhanced the phosphorylation of MLC. The MLC phosphorylation was mediated through increased abundance of MLCK and inhibition of myosin light chain phosphatase latest known to be inversely regulated by RhoA. Contrary to others, in our model genistein did neither inhibit the cardiac MLCK, nor the cardiac RhoA pathway in vivo.


Journal of Protein Chemistry | 1999

Stability of Some Cactaceae Proteins Based on Fluorescence, Circular Dichroism, and Differential Scanning Calorimetry Measurements

Shela Gorinstein; Marina Zemser; Francisco Vargas-Albores; José-Luís Ochoa; Octavio Paredes-López; Christian Scheler; Sevil Aksu; Johann Salnikow

Characterization of three cactus proteins (native and denatured) from Machaerocereus gummosus (Pitahaya agria), Lophocereu schottii (Garambullo), and Cholla opuntia (Cholla), was based on electrophoretic, fluorescence, CD (circular dichroism), DSC (differential scanning calorimetry), and FT-IR (Fourier transform infrared) measurements. The obtained results of intrinsic fluorescence, DSC, and CD were dissimilar for the three species of cactus, providing evidence of differences in secondary and tertiary structures. Cactus proteins may be situated in the following order corresponding to their relative stability: Machaerocereus gummosus (Pitahaya agria) > Cholla opuntia (Cholla) > Lophocereu schottii (Garambullo). Thermodynamic properties of proteins and their changes upon denaturation (temperature of denaturation, enthalphy, and the number of ruptured hydrogen bonds) were correlated with the secondary structure of proteins and disappearance of α-helix.


Physiological Entomology | 2018

Protein analysis of the spermatophore reveals diverse compositions in both the ampulla and the spermatophylax in a bushcricket

Gerlind U. C. Lehmann; Karola Lehmann; Boris Neumann; Arne W. Lehmann; Christian Scheler; Peter R. Jungblut

Nuptial gifts are male mating investments, which, in bushcrickets, comprise the sperm‐containing ampulla and the attached spermatophylax. The functions of the spermatophylax are to deter females from premature removal of the sperm‐containing ampulla, which is a nutrient resource for females, as well as a source of compounds that influence female behaviour to increase male evolutionary fitness. Placing these functions into a proteomic perspective, we analyze the protein composition of nuptial gifts from male Poecilimon ampliatus (Brunner von Wattenwyl, 1878) bushcrickets using large two‐dimensional gel electrophoresis coupled with nano‐liquid chromatography‐electrospray ionization mass spectrometry and de novo sequencing. We separate the proteins with high resolution and detect approximately 600 protein spots in the seminal fluid (ampulla) and 300 in the spermatophylax. There is only a small fraction of overlap in protein spots, whereas the majority differ between the two compartments. As a result of the lack of a sequenced genome and protein data for this non‐model insect, we are unable to identify the proteins. We discuss the diversity of proteins, as well as their size range, in light of potential protein costs and potential functions.


Journal of Proteomics | 2017

Sex differences in murine myocardium are not exclusively regulated by gonadal hormones

Franz Theuring; Boris Neumann; Christian Scheler; Peter R. Jungblut; Karima Schwab

We investigated sex differences in cardiac protein patterns of intact and castrated mice using proteomics and 1D and 2D immunoblotting. To exclude differences concerning developmental aspects gonadectomy was conducted in mature mice at the age of three months. The main sex-related regulation in the protein pattern of the myocardium occurred for proteins involved in metabolic processes whereas only few proteins involved in other pathways underwent a regulation. Many regulated proteins (2/3) displayed a characteristic V form, which means that these proteins are up- or down-regulated in sexually mature compared to young mice and are back-regulated after castration, emphasizing a direct regulation by gonadal hormones. Several other spots (1/3) showed the same male/female regulation or a drastic increase in male/female spot intensity ratio after castration, suggesting either a regulation independent of sex hormones or a removal of an inhibiting feedback mechanism by gonadectomy. Technically, we found that it cannot be expected that a single spot contains only one protein species and that one protein is present in only one spot. We thus propose for proteomic investigations to identify/quantify all spots of a 2-DE pattern to obtain information about protein speciation and its potential importance for function and pathology. BIOLOGICAL SIGNIFICANCE Sex related differences in cardiovascular disease, including risk factors, disease manifestation and outcomes, are far from being well understood, and improved biological understanding of these differences in the healthy myocardium is of great importance. We investigated sex related changes of myocardial protein pattern in intact and castrated mice at different ages and found metabolic proteins to be highly regulated, some of which independently from gonadal hormones.

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Johann Salnikow

Technical University of Berlin

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Eva-Christina Müller

Max Delbrück Center for Molecular Medicine

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Karima Schwab

Humboldt University of Berlin

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Albrecht Otto

Max Delbrück Center for Molecular Medicine

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Michael W. Linscheid

Humboldt University of Berlin

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