@article{MuellerDieckmannSebaldetal.1994,
  author    = {M{\"u}ller, T. and Dieckmann, T. and Sebald, Walter and Oschkinat, H.},
  title     = {Aspects of receptor binding and signalling of interleukin-4 investigated by site-directed mutagenesis and NMR spectroscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62444},
  year      = {1994},
  abstract  = {Cytokines are hormones that carry information from ceJI to ceH. This information is read from their surface upon binding to transmembrane receptors and by the subsequent initiation of receptor oligomerization. An inftuence on this process through mutagenesis on the hormone surface is highly desirab)e for medical reasons. However, an understanding of hormone-receptor interactions requires insight into the structural changes introduced by the mutations. In this line structural studies on human TL-4 and the medically important IL-4 antagonists YI24D and Y124G are presented. The site a.round YI24 is an important epitope responsible for the a.bility of 11-4 t.o ca.use a signal in the target cells. It is shown that the local main-chain structure around residue 124 in the variants remains unchanged. A strategy is presented here which allows the study of these types of proteins and their variants by NMR which does not require carbon Iabeiied sa.mples.},
  subject      = {Biochemie},
  language  = {en}
}
@article{MuellerSebaldOschkinat1994,
  author    = {M{\"u}ller, T. and Sebald, Walter and Oschkinat, H.},
  title     = {Antagonist design through forced electrostatic mismatch},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62408},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{ReuschArnoldHeusseretal.1994,
  author    = {Reusch, P. and Arnold, S. and Heusser, C. and Wagner, K. and Weston, B. and Sebald, Walter},
  title     = {Neutralizing monoclonal antibodies define two different functional sites in human interleukin-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62418},
  year      = {1994},
  abstract  = {Human interleukin-4 (IL-4) is a small four-helix-bundle protein which is essential for organizing defense reactions against macroparasites, in particular helminths. Human IL-4 also appears to exert a pathophysiological role during various IgE-mediated allergic diseases. Seven different monoclonal antibodies neutralizing the activity of human IL-4 were studied in order to identify functionally important epitopes. A collection of 41 purified IL-4 variants was used to analyse how defined amino acid replacements affect binding affinity for each individual mAb. Specific amino acid positions could be assigned to four different epitopes. mAbs recognizing epitopes on helix A and/or C interfered with IL-4 receptor binding and thus inhibited IL-4 function. However, other mAbs also inhibiting IL-4 function recognized an epitope on helix D of IL-4 and did not inhibit IL-4 binding to the receptor protein. One mAb, recognizing N-terminal and C-terminal residues, partially competed for binding to the receptor. The results of these mAb epitope analyses confirm and extend previous data on the functional consequences of the amino acid replacements which showed that amino acid residues in helices A and C of IL-4 provide a binding site for the cloned IL-4 receptor and that a signalling site in helix D interacts with a further receptor protein.},
  subject      = {Biochemie},
  language  = {en}
}
@article{DemchukMuellerOschkinatetal.1994,
  author    = {Demchuk, E. and Mueller, T. and Oschkinat, H. and Sebald, Walter and Wade, R. C.},
  title     = {Receptor binding properties of four-helix-bundle growth factors deduced from electrostatic analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62424},
  year      = {1994},
  abstract  = {Hormones of the hematopoietin class mediate signal transduction by binding to specific transmembrane receptors. Structural data show that the human growth hormone (hGH) forms a complex with a homodimeric receptor and that hGH is a member of a class of hematopoietins possessing an antiparallel 4-a-helix bundle fold. Mutagenesis experiments suggest that electrostatic interactions may have an important influence on hormonereceptor recognition. In order to examine the specificity of hormone-receptor complexation, an analysis was made of the electrostatic potentials of hGH, interleukin-2 (IL-2), interleukin-4 (IL-4), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and the hGH and IL-4 receptors. The binding surfaces of hGH and its receptor, and of IL-4 and its receptor, show complementary electrostatic potentials. The potentials of the hGH and its receptor display approximately 2-fold rotational symmetry because the receptor subunits are identical. In contrast, the potentials of GM-CSF and IL-2 Iack such symmetry, consistent with their known high affinity for hetero-oligomeric receptors. Analysis of the electrostatic potentials supports a recently proposed hetero-oligomeric model for a high-affinity IL-4 receptor and suggests a possible new receptor binding mode for G-CSF; it also provides valuable information for guiding structural and mutagenesis studies of signal-transducing proteins and their receptors.},
  subject      = {Biochemie},
  language  = {en}
}
@article{LehrnbecherPootOrschescheketal.1994,
  author    = {Lehrnbecher, T. and Poot, M. and Orscheschek, K. and Sebald, Walter and Feller, A. C. and Merz, H.},
  title     = {Interleukin 7 as interleukin 9 drives phytohemagglutinin-activated T cells through several cell cycles; no synergism between interleukin 7, interleukin 9 and interleukin 4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62438},
  year      = {1994},
  abstract  = {The effects of the interlenkins IL-7 and IL-9 on cell cycle progression were investigated by conventional [3H]thymidine incorporation and by the bivariate BrdU/Hoechst technique. 8oth IL· 7 and IL-9 drive phytohemagglutinin-activated T cells through more than one cell cycle, but IL-7 wasmorepotent on cell cycle progression than IL-9. Neither synergistic nor inhibitory effects were seen between various combinations of the lymphokines IL-7, IL-9 and IL-4 compared to each lymphokine alone. When T cells are activated with phytohemagglutinin for 3 days, all or most IL-4 responsive cells respond to IL-7 as weil, whereas only a part of IL-7 responders are IL-4 responders. In contrast, when T cells are activated with phytohemagglutinin for 7 days, the quantitative data of the cell cycle distribution soggest that the population of IL-7 responders is at least an overlapping, if not a real subset of the population of the IL-4 responders.},
  subject      = {Biochemie},
  language  = {en}
}
@article{KueblerReutherKirchneretal.1994,
  author    = {K{\"u}bler, N. and Reuther, J. and Kirchner, T. and Pfaff, M. and M{\"u}ller-Hermelink, H. K. and Albert, R. and Sebald, Walter},
  title     = {IgG monoclonal antibodies that inhibit osteoinductivity of human bone matrix-derived proteins (hBMP/NCP)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62388},
  year      = {1994},
  abstract  = {Monoclonal hBMP/NCP (human bone morphogenetic protein anrl associaterl noncollagenous proteins) antiborlies of the lgG class were prorlucerl. In vitro, 12 of 19 hBMP/NCP antiborlies showerl functional inhibition of hBMP/ NCP-induced chondroneogenesis in a neonatal muscle tissue assay. Inducing factors were characterized by their inhibiting antibodies with immunoblotting. Several peptide factors seem to be involved in the cascade of inducerl chondro- and osteogenesis.},
  subject      = {Biochemie},
  language  = {en}
}
@article{TonyShenReuschetal.1994,
  author    = {Tony, H. P. and Shen, B. J. and Reusch, P. and Sebald, Walter},
  title     = {Design of human interleukin-4 antagonists inhibiting interleukin-4-dependent and interleukin-13-dependent responses in T-cells and B-cells with high efficiency},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62394},
  year      = {1994},
  abstract  = {Human interleukin-4 possesses two distinct sites for receptor activation. A signaHing site, comprising residues near the C-terminus on helix D, determines the efficacy of interleukin-4 signal transduction without affecting the binding to the interleukin-4 receptor a subunit. A complete antagonist and a series of low-efficacy agonist variants of human interleukin-4 could be generated by introducing combinations of two or three negatively charged aspartic acid residues in this site at positions 121, 124, and 125. One of the double variants, designated [R121D,Y124D]interleukin-4, with replacements of b{\"o}th Arg121 and Tyr124 by aspartic acid residues was completely inactive in all analysed cellular responses. The loss of efficacy in [R121D,Y124D]interleukin-4 is estimated to be larger than 2000-fold. Variant [R121D,Y124D]interleukin-4 was also a perfect antagonist for inhibition of interleukin-13-dependent responses in B-cells and the TF-1 cellline with a K\(_i\) value of approximately 100 pM. In addition, inhibition of both interleukin-4-induced and interleuk.in-13- induced responses could be obtained by monoclonal antibody X2/45 raised against interleukin-4Rm the extracellular domain of the interleuk.in-4 receptor a subunit. These results indicate that efficient interleukin-4 antagonists can be designed on the basis of a sequential two-step activation model. In addition, the experiments indicate the functional participation of the interleukin-4 receptor a subunit in the interleukin-13 receptor system.},
  subject      = {Biochemie},
  language  = {en}
}
@article{HarthKotzschHuetal.2010,
  author    = {Harth, Stefan and Kotzsch, Alexander and Hu, Junli and Sebald, Walter and Mueller, Thomas D.},
  title     = {A Selection Fit Mechanism in BMP Receptor IA as a Possible Source for BMP Ligand-Receptor Promiscuity},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68497},
  year      = {2010},
  abstract  = {Background: Members of the TGF-b superfamily are characterized by a highly promiscuous ligand-receptor interaction as is readily apparent from the numeral discrepancy of only seven type I and five type II receptors available for more than 40 ligands. Structural and functional studies have been used to address the question of how specific signals can be deduced from a limited number of receptor combinations and to unravel the molecular mechanisms underlying the protein-protein recognition that allow such limited specificity. Principal Findings: In this study we have investigated how an antigen binding antibody fragment (Fab) raised against the extracellular domain of the BMP receptor type IA (BMPR-IA) recognizes the receptor's BMP-2 binding epitope and thereby neutralizes BMP-2 receptor activation. The crystal structure of the complex of the BMPR-IA ectodomain bound to the Fab AbD1556 revealed that the contact surface of BMPR-IA overlaps extensively with the contact surface for BMP-2 interaction. Although the structural epitopes of BMPR-IA to both binding partners coincides, the structures of BMPR-IA in the two complexes differ significantly. In contrast to the structural differences, alanine-scanning mutagenesis of BMPR-IA showed that the functional determinants for binding to the antibody and BMP-2 are almost identical. Conclusions: Comparing the structures of BMPR-IA bound to BMP-2 or bound to the Fab AbD1556 with the structure of unbound BMPR-IA shows that binding of BMPR-IA to its interaction partners follows a selection fit mechanism, possibly indicating that the ligand promiscuity of BMPR-IA is inherently encoded by structural adaptability. The functional and structural analysis of the BMPR-IA binding antibody AbD1556 mimicking the BMP-2 binding epitope may thus pave the way for the design of low-molecular weight synthetic receptor binders/inhibitors.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{SeherNickelMuelleretal.2011,
  author    = {Seher, Axel and Nickel, Joachim and Mueller, Thomas D. and Kneitz, Susanne and Gebhardt, Susanne and Meyer ter Vehn, Tobias and Schlunck, Guenther and Sebald, Walter},
  title     = {Gene expression profiling of connective tissue growth factor (CTGF) stimulated primary human tenon fibroblasts reveals an inflammatory and wound healing response in vitro},
  series = {Molecular Vision},
  volume    = {17},
  journal   = {Molecular Vision},
  number    = {08. Okt},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140189},
  pages     = {53-62},
  year      = {2011},
  abstract  = {Purpose: The biologic relevance of human connective tissue growth factor (hCTGF) for primary human tenon fibroblasts (HTFs) was investigated by RNA expression profiling using affymetrix (TM) oligonucleotide array technology to identify genes that are regulated by hCTGF. Methods: Recombinant hCTGF was expressed in HEK293T cells and purified by affinity and gel chromatography. Specificity and biologic activity of hCTGF was confirmed by biosensor interaction analysis and proliferation assays. For RNA expression profiling HTFs were stimulated with hCTGF for 48h and analyzed using affymetrix (TM) oligonucleotide array technology. Results were validated by real time RT-PCR. Results: hCTGF induces various groups of genes responsible for a wound healing and inflammatory response in HTFs. A new subset of CTGF inducible inflammatory genes was discovered (e.g., chemokine [C-X-C motif] ligand 1 [CXCL1], chemokine [C-X-C motif] ligand 6 [CXCL6], interleukin 6 [IL6], and interleukin 8 [IL8]). We also identified genes that can transmit the known biologic functions initiated by CTGF such as proliferation and extracellular matrix remodelling. Of special interest is a group of genes, e.g., osteoglycin (OGN) and osteomodulin (OMD), which are known to play a key role in osteoblast biology. Conclusions: This study specifies the important role of hCTGF for primary tenon fibroblast function. The RNA expression profile yields new insights into the relevance of hCTGF in influencing biologic processes like wound healing, inflammation, proliferation, and extracellular matrix remodelling in vitro via transcriptional regulation of specific genes. The results suggest that CTGF potentially acts as a modulating factor in inflammatory and wound healing response in fibroblasts of the human eye.},
  language  = {en}
}
@article{MuellerFiebigWeidaueretal.2013,
  author    = {Mueller, Thomas D. and Fiebig, Juliane E. and Weidauer, Stella E. and Qiu, Li-Yan and Bauer, Markus and Schmieder, Peter and Beerbaum, Monika and Zhang, Jin-Li and Oschkinat, Hartmut and Sebald, Walter},
  title     = {The Clip-Segment of the von Willebrand Domain 1 of the BMP Modulator Protein Crossveinless 2 Is Preformed},
  series = {Molecules},
  journal   = {Molecules},
  doi       = {10.3390/molecules181011658},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97196},
  year      = {2013},
  abstract  = {Bone Morphogenetic Proteins (BMPs) are secreted protein hormones that act as morphogens and exert essential roles during embryonic development of tissues and organs. Signaling by BMPs occurs via hetero-oligomerization of two types of serine/threonine kinase transmembrane receptors. Due to the small number of available receptors for a large number of BMP ligands ligand-receptor promiscuity presents an evident problem requiring additional regulatory mechanisms for ligand-specific signaling. Such additional regulation is achieved through a plethora of extracellular antagonists, among them members of the Chordin superfamily, that modulate BMP signaling activity by binding. The key-element in Chordin-related antagonists for interacting with BMPs is the von Willebrand type C (VWC) module, which is a small domain of about 50 to 60 residues occurring in many different proteins. Although a structure of the VWC domain of the Chordin-member Crossveinless 2 (CV2) bound to BMP-2 has been determined by X-ray crystallography, the molecular mechanism by which the VWC domain binds BMPs has remained unclear. Here we present the NMR structure of the Danio rerio CV2 VWC1 domain in its unbound state showing that the key features for high affinity binding to BMP-2 is a pre-oriented peptide loop.},
  language  = {en}
}