@article{KruseLehrnbecherSebald1991, author = {Kruse, N. and Lehrnbecher, T. and Sebald, Walter}, title = {Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62505}, year = {1991}, abstract = {Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.}, subject = {Biochemie}, language = {en} } @article{SchwabSebaldWeiss1972, author = {Schwab, A. J. and Sebald, Walter and Weiss, H.}, title = {Schnelle Markierung eines mitochondrial synthetisiertem Polypeptids einer Cytochromoxidasen-Pr{\"a}paration aus Neurospora}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-84206}, year = {1972}, abstract = {no abstracts available}, subject = {Physiologische Chemie}, language = {de} } @article{OnoSonoyamaNemaetal.2014, author = {Ono, Mitsuaki and Sonoyama, Wataru and Nema, Kazuki and Hara, Emilio Satoshi and Oida, Yasutaka and Pham, Hai Thanh and Yamamoto, Katushi and Hirota, Kazuo and Sugama, Kazushige and Sebald, Walter and Kuboki, Takuo}, title = {Regeneration of calvarial defects with Escherichia coli-derived rhBMP-2 adsorbed in PLGA membrane}, series = {Cells Tissues Organs}, volume = {198}, journal = {Cells Tissues Organs}, number = {5}, issn = {1422-6405}, doi = {10.1159/000356947}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196680}, pages = {367 -- 376}, year = {2014}, abstract = {Objective: Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E-BMP-2) has been shown to be as effective as mammalian cell-derived BMP-2. However, several in vitro and in vivo experiments are still necessary to validate the effectiveness of E-BMP-2 due to the difference in synthesis process, mainly related to protein nonglycosylation. The objective of this study was to investigate whether biodegradable polylactide-co-glycolide (PLGA) membrane is a suitable carrier for E-BMP-2 delivery for bone regeneration of critical-sized defects in rat calvaria. Materials and Methods: First, the osteoinductive effect of E-BMP-2 was confirmed in vitro in mouse bone marrow stromal cells by analysis of osteocalcin mRNA levels, and calcium deposition was detected by alizarin red staining. Before in vivo experiments, the release profile of E-BMP-2 from PLGA membranes was determined by ELISA. E-BMP-2 (0, 1, 5 and 10 μg/μl) was applied for ectopic and orthotopic bone formation and was analyzed by X-ray, micro-CT and histology. Results: Release-profile testing showed that PLGA membrane could retain 94\% of the initially applied E-BMP-2. Ectopic bone formation assay revealed that combination of E-BMP-2/PLGA membrane strongly induced bone formation. Stronger osteoinductivity with complete repair of critical-sized defects was observed only with PLGA membranes adsorbed with 5 and 10 μg/μl of E-BMP-2, whereas no bone formation was observed in the groups that received no membrane or 0-μg/μl dose of E-BMP-2. Conclusion: PLGA membrane was shown to be a suitable carrier for sustained release of E-BMP-2, and the E-BMP-2/PLGA membrane combination was demonstrated to be efficient in bone regeneration in a model of critical-sized defects.}, 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{NeupertSebaldSchwabetal.1969, author = {Neupert, W. and Sebald, Walter and Schwab, A. J. and Pfaller, A. and B{\"u}cher, T.}, title = {Puromycin sensitivity of ribosomal label after incorporation of \(^{14}\)C-labelled amino acids into isolated mitochondria from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62899}, year = {1969}, abstract = {Radioactive amino acids were incorporated into isolated mitochondria from Neurospora crassa. Then the mitochondrial ribosomes were isolated and submitted to density gradient centrifugation. A preferential labelling of polysomes was observed. However, when the mitochondrial suspension was treated with puromycin after amino acid incorporation, no radioactivity could be detected in either the monosomes or the polysomes. The conclusion is drawn that isolated mitochondria under these conditions do not incorporate significant amounts of amino acids into proteins of their ribosomes.}, subject = {Biochemie}, language = {en} } @article{WeissSebald1978, author = {Weiss, H. and Sebald, Walter}, title = {Purification of cytochrome oxidase from Neurospora crassa and other sources}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82082}, year = {1978}, abstract = {A chromatographic procedure 1 is described by means of which cytochrome oxidase has been purified from a variety of organisms including the fungus N eurospora crassa,2,3 the unicellular alga Po/ytoma mirum, 4 the insect Locusta migratoria ,5 the frog Xenopus muel/eri,4 and the mammal Rattus norwegicus. 4 This procedure can be used to equal effect for large-scale preparations, starting from grams of mitochondrial protein, or for small-scale preparations starting from milligrams. The cytochrome oxidase preparations from the different organisms are enzymically active. They show similar subunit compositions.}, subject = {Biochemie}, language = {en} } @article{SebaldMachleidtOtto1973, author = {Sebald, Walter and Machleidt, W. and Otto, J.}, title = {Products of mitochondrial protein synthesis in Neurospora crassa. Determination of equimolar amounts of three products in cytochrome oxidase on the basis of amino-acid analysis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62827}, year = {1973}, abstract = {Cytochrome oxidase isolated from N eurospora crassa was resolved into seven protein eomponents by eleetrophoresis in polyaerylamide gels eontaining sodium dodeeylsulfate. The apparent molecular weights were determined tobe 41000, 28500, 21000, 16000, 14000, 11500 and 10000 for the eomponents 1, 2, 3, 4, 5, 6, and 7, respectively. The components 1, 2 and 3 are synthesized on mitochondrial ribosomes as shown by the incorporation of radioactive amino aeids in the presenee of cyeloheximide. Amino-acidanalysis of the isolated components 1, 2 and 3 revealed a high content of apolar amino acids and a low eontent of basic amino aeids compared to an average amino-aeid eomposition of components 4-7. Components 1, 2 and 3 eontribute 27.9°/0, 18°/0 and 14.2°/0 to the whole eytoehrome oxidase protein. This was calculated from the contributions of the single eomponents to the totalleueine eontent of the enzyme and the leueine eontents (nmol leueine per mg protein) of the single eomponents as determined by amino-aeid analysis. Equimolar relations of the components 1, 2 and 3 are found by dividing the amounts of protein by their apparent molecular weights. A stoichiometry of 1:1:1 results assuming a minimal molecular weight of 150000 for the whole cytochrome oxidase protein. On the basis of the heme a content a molecular weight of about 70000 per heme group was determined, using an absorption coeffieient L1e605 (redueed minus oxidized) of 12 mM-1 cm-1• It is concluded that the smallest structural unit of eytochrome oxidase contains two heme groups.}, subject = {Biochemie}, language = {en} } @article{SchmidtWachterSebaldetal.1984, author = {Schmidt, B. and Wachter, E. and Sebald, Walter and Neupert, W.}, title = {Processing peptidase of Neurospora mitochondria. Two-step cleavage of imported ATPase subunit 9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62674}, year = {1984}, abstract = {Subunit 9 (dicyclohexylcarbod{\"u}mide binding protein, 'proteolipid') of the mitochondrial F 1F0-ATPase is a nuclearly coded protein in Neurospora crassa. lt is synthesized on free cytoplasmic ribosomes as a larger precursor with an NH2-terminal peptide extension. The peptide extension is cleaved ofT after transport of the protein into the mitochondria. A processing activity referred to as processing peptidase that cleaves the precursor to subunit 9 and other mitochondrial proteins is described and characterized using a cell-free system. Precursor synthesized in vitro was incubated with extracts of mitochondria. Processing peptidase required Mn2 + for its activity. Localization studies suggested that it is a soluble component of the mitochondrial matrix. The precursor was cleaved in two sequential steps via an intermediate-sized polypeptide. The intermediate form in the processing of subunit 9 was also seen in vivo and upon import of the precursor into isolated mitochondria in vitro. The two dcavage sites in the precursor molecule were determined. The data indicate that: {a) the correct NH2-terminus of the mature protein was generated, (b) the NH2-terminal amino acid of the intermediate-sized polypeptide is isoleueine in position -31. The cleavage sites show similarity ofprimary structure. It is concluded that processing peptidase removes the peptide extension from the precursor to subunit 9 (and probably other precursors) after translocation of these polypeptides (or the NHrterminal part of these polypeptides) into the matrix space of mitochondria.}, subject = {Biochemie}, language = {en} } @article{SebaldNeupertWeiss1979, author = {Sebald, Walter and Neupert, W. and Weiss, H.}, title = {Preparation of Neurospora crassa mitochondria}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82070}, year = {1979}, abstract = {The fungus Neurospora crassa represents a eukaryotic cell with high biosynthetic activities. Cell mass doubles in 2-4 hr during expone ntial growth , even in simple salt media with sucrose as the sole carbon source. The microorgani sm forms a mycelium of long hyphae durlng vegetative growth . The mitochondria can be isolated under relatively gentle condi tions since a few breaks in the threadlike hyphae are sufficient to cause the outflow of the organelles. This article describes two methods for the physical disruption of the hyphae : (I) The cell s are opened in a grind mill between two rotating corundum di sks. This is a continuous and fast procedure and allows large- and small-scale preparations of mitochondria. (2) Hyphae are ground with sand in a mortar and pestle. This procedure can be applied to microscale preparations of mitochondria starting with minute amounts of cells. Other procedures for the isolation of Neurospora mitochondria after the physical di sruption or the enzymatic degradation of the cell wall have been described elsewhere}, subject = {Biochemie}, language = {en} } @article{KueblerReutherKirchneretal.1993, author = {K{\"u}bler, Norbert and Reuther, J{\"u}rgen and Kirchner, Thomas and Priessnitz, Bernd and Sebald, Walter}, title = {Osteoinductive, morphologic, and biomechanical properties of autolyzed, antigen-extracted, allogeneic human bone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86715}, year = {1993}, abstract = {Autolyzed, antigen-extracted, allogeneic (AAA) bone was prepared from human cortical bone and its morphologic, biomechanical, and osteoinductive properlies were compared with untreated (frozen) as well as lyophilized human bone. Scanning electron microscopy revealed removal of inprganic calcium phosphates and persistence of shrunken collagen fibrils on the surface of AAA bone matrix. Biomechanical testing of differently prepared bone samples showed that lyophilization increased both the modulus of elasticity (P < .00001) and the compressive strength (P < .00001 ). Depending on the depth of decalcification in the preparation of AAA bone, both measured values decreased in rehydrated AAA bone compared with untreated bone {P < .00001 ). Completely demineralized and rehydrated AAA bone was soft, flexible, and showed very little compressive strength. Differences in biomechanical behavior between samples drilled longitudinally or perpendicularly to the diaphyseal bone axis were observed. Xenogeneic human bone samples were implanted in muscle pouches of Sprague-Dawley rats for 6 weeks. AAA bone implants showed chondrogenesis and osteogenesis in 50\% of the cases, while untreated or lyophilized bone implants induced no new cartilage or bone formation. As decalcification exposed xenogeneic organic matrix components, AAA bone implants provoked the highest inflammatory reaction. When AAA bone samples were implanted in immunosuppressed rats, the inflammatory reaction was suppressed and 94o/o of the implants showed endochondral bone formation. The chondroinductivity of the bone samples also was tested in vitro using neonatal rat muscle tissue to avoid interference with inflammatory cells and secreted cytokines. In this assay, 68°/o of AAA bone samples induced chondroneogenesis, while untreated as weil as lyophilized bone samples failed to induce any cartilage formation. The results clearly dernonstrafe that AAA bone has osteoinductive properties. Biomechanical stability of AAA bone implants depends on the degree of demineralization. Thus, they can be prepared in an appropriate manner for different indications in oral and maxillofacial surgery.}, subject = {Mund-Kiefer-Gesichts-Chirurgie}, language = {en} } @article{ArendsSebald1984, author = {Arends, H. and Sebald, Walter}, title = {Nucleotide sequence of the cloned mRNA and gene of the ADP/ATP carrier from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62684}, year = {1984}, abstract = {A cDNA complementary to the mRNA of the ADPIATP carrier from Neurospora crassa was identified among ordered cDNA clones by hybridizing total polyadenylated RNA to pools of 96 cDNA recombinant plasmids and subsequent cellfree translation of hybridization-selected mRNA. Further carrier cDNAs were found by colony fdter hybridization at a frequency of 0.2-0.3\%. The gene of the carrier was cloned and isolated on a 4.6-kbp EcoRl fragment of total Neurospora DNA, and the start of the mRNA was determined by Sl nuclease mapping. From the nucleotide sequence of the cDNA and the genomic DNA, the primary structure of the gene, of the mRNA and of the ADP I ATP carrier protein could be deduced. The gene occurs in a single copy in the genome and related genes are absent. It contains two short introns, and a pyrimidine-rieb promoter region. The mRNA has a 46-bp 5 1 end and a 219-bp 3 1 end. There is an open reading frame coding for the 313 amino acid residues of the Neurospora carrier protein. The amino acid sequence is homologous in 148 positions with the established primary structure of the beef heart carrier.}, subject = {Biochemie}, language = {en} } @article{GabelliniSebald1986, author = {Gabellini, N. and Sebald, Walter}, title = {Nucleotide sequence and transcription of the fbc operon from Rhodopseudomonas sphaeroides. Evaluation of the deduced amino acid sequences of the FeS protein, cytochrome b and cytochrome c\(_1\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62615}, year = {1986}, 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{SebaldMachleidtWachter1980, author = {Sebald, Walter and Machleidt, Werner and Wachter, Elmar}, title = {N,N'-dicyclohexylcarbodiimide binds specifically to a single glutamyl residue of the proteolipid subunit of the mitochondrial adenosinetriphosphatases from Neurospora crassa and Saccharomyces cerevisiae}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47394}, year = {1980}, abstract = {T~e N,N'-dicrclohexylcarbodiimide-binding proteolipid subumt of the mitochondrial adenosinetriphosphatases (ATP phosphohydrolase, EC 3.6.1.3) of Neurosporacrassa and Saccharomyces cerevisiae were purified from mitochondria incubated with the radioactively labeled inhibitor. The specifically labeled subunit was cleaved with cyanogen bromide and N-bromosuccinimide, and the resultant fragments were separated by gel chromatography in the presence of 80\% (vol/vol) formic acid. The N,N'-dicyclohexylcarbodiimide label was recovered in each organism exclusively in a 17-residue fragment. Further analysis by automated solid-phase Edman degrada.ti.on revealed tha~ the bound label was present at only one positIOn, correspondmg to a glutamyl residue. The NN'~ icyc~ohexyl~a~bodiiJ?1~de-'!l0dified glutamyl residue is the ~nly Id~ntIcal aCidic posItIon m both proteins and occurs in the middle of a hydrophobic sequence of about 25 residues.}, subject = {Dicyclohexylcarbodiimid}, language = {en} } @article{WeigelMeyerSebald1989, author = {Weigel, U. and Meyer, M. and Sebald, Walter}, title = {Mutant proteins of human interleukin 2. Renaturation yield, proliferative activity and receptor binding}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62543}, year = {1989}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{ViebrockPerzSebald1983, author = {Viebrock, A and Perz, A and Sebald, Walter}, title = {Molecular cloning of middle-abundant mRNAs from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82033}, year = {1983}, abstract = {no abstract available}, subject = {Neurospora crassa}, language = {en} } @article{KleenePfannerPfalleretal.1987, author = {Kleene, R. and Pfanner, N. and Pfaller, R. and Link, T. A. and Sebald, Walter and Neupert, W. and Tropschug, M.}, title = {Mitochondrial porin of Neurospora crassa: cDNA cloning, in vitro expression and import into mitochondria}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62566}, year = {1987}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{TzagoloffMacinoSebald1979, author = {Tzagoloff, A. and Macino, G. and Sebald, Walter}, title = {Mitochondrial genes and translation products}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47408}, year = {1979}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{SebaldWild1979, author = {Sebald, Walter and Wild, G.}, title = {Mitochondrial ATPase complex from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82065}, year = {1979}, abstract = {The A TPase eomplex has been isolated from mitoehondria of N eurospora crassa by immunologieal teehniques. The protein ean be obtained rapidly and qua ntitatively in high purity by miero- or large-seale immunopreeipitation. Immunopreeipitation has been applied to labeled and doubly labeled mitoehondrial proteins in order to investigate the number and moleeular weights of subunit polypeptides , the site of synthesis of subunit polypeptides, and the dieycIohexyIcarbodiimide-binding protein . The A TPase complex obtained by large-seale immunopreeipitation has been used as starting ma terial for the isolation of hydrophobie polypeptides.}, subject = {Biochemie}, language = {en} } @article{HoppeGattiWeberetal.1986, author = {Hoppe, J. and Gatti, D. and Weber, H. and Sebald, Walter}, title = {Labeling of individual amino acid residues in the membrane-embedded F\(_0\) part of the F\(_1\) F\(_0\) ATP synthase from Neurospora crassa. Influence of oligomycin and dicyclohexylcarbodiimide}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62598}, year = {1986}, abstract = {Three F0 subunits and the F\(_1\) subunit P of the ATP synthase from Neurospora crassa were labeled with the lipophilic photoactivatable reagent 3-(trifluoromethyl)-3-(m-[\(^{125}\)I]iodophenyl)diazirine ([\(^{125}\)I]TID). In the proteolipid subunit which was the most heavily labeled polypeptide labeling was confmed to five residues at the NH2-terminus and five residues at the C-terminus ofthe protein. Labeling occurred at similar positions compared with the homologaus protein (subunit c) in the ATP synthase from Escherichia coli, indicating a similar structure of the proteolipid subunits in their respective organisms. The inhibitors oligomycin and dicyclohexylcarbodiimide did not change the pattern of accessible surface residues in the proteolipid, suggesting that neither inhibitor induces gross conformational changes. However, in the presence of oligomycin, the extent oflabeling in some residues was reduced. Apparently, these residues provide part of the binding site for the inhibitor. After reaction with dicyclohexylcarbodiimide an additional labeled amino acid was found at position 65 corresponding to the invariant carbod{\"u}mide-binding glutamic acid. These results and previous observations indicate that the carboxyl side chain of Glu-65 is located at the protein-lipid interphase. The idea is discussed that proton translocation occurs at the interphase between different types if F\(_0\) subunits. Dicyclohexylcarbodiimide or oligomycin might disturb this essential interaction between the F\(_0\) subunits.}, subject = {Biochemie}, language = {en} }