@article{SebaldNeupertBirkmayer1970, author = {Sebald, Walter and Neupert, W. and Birkmayer, G. D.}, title = {Internal and external contributions to the biogenesis of mitochondrial proteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62876}, year = {1970}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{WeissSebaldBuecher1971, author = {Weiss, H. and Sebald, Walter and B{\"u}cher, T.}, title = {Cycloheximide resistant incorporation of amino acids into a polypeptide of the cytochrome oxidase of Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62866}, year = {1971}, abstract = {Radioaetive leueine was ineorporated by N eurospora crassa mitoehondria in vivo in the presence of cyeloheximide. When the membrane protein of these mitochondria was ehromatographieally separated on oleyl polymethaerylie aeid resin, \& nurober of fraetions were obtained whieh differ with respeet to their eontents of radioaetivity and eytoehromes. The highest speeifie radioaetivity was found in the fraction eontaining eytoehrome aa3• This fraetion proved to be a pure and enzymatically aetive cytoehrome oxidase. Its ratio of absorbanee at 280 nm (ox)/ 443 nm (red.) was 2.1. By means of sodium dodeeylsulfate gel-electrophoresis, this enzymewas separated into five polypeptides with molecular weights of 30000, 20000, 13000, 10000, and 8000. Only the polypeptide with the molecular weight 20000 displayed a high specific radioaetivity.}, subject = {Biochemie}, language = {en} } @article{SebaldWeissJackl1972, author = {Sebald, Walter and Weiss, H. and Jackl, G.}, title = {Inhibition of the assembly of cytochrome oxidase in Neurospora crassa by chloramphenicol}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62852}, year = {1972}, abstract = {Cytochrome oxidasewas prepared from Neurospora crassa by chromatography on oleyl polymethacrylic acid resin and separated into seven polypeptides by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. Incorporation oflabelled amino acids into the single polypeptideswas investigated after a pulse labelling in the absence and presence of chloramphenicol, and afterwashing out the inhibitor. Chloramphenicol (4 mg/ml) inhibited amino acid incorporation into all polypeptides 90-95\%• while labeHing of the whole membrane protein was inhibited only 30\%• Mter washing out the inhibitor and further growth of the cells. the four smaller polypeptides were highly labelled, whereas the other polypeptides showed only a. small increase in radioactivity. It is concluded that the four small-sized polypeptides of cytochrome oxidase are synthesized but not integrated into the functional enzyme under the action of chloramphenicol.}, subject = {Biochemie}, language = {en} } @article{SchwabSebaldWeiss1972, author = {Schwab, A. J. and Sebald, Walter and Weiss, H.}, title = {Different pool sizes of the precursor polypeptides of cytochrome oxidase from Neurospora crassa.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62841}, year = {1972}, abstract = {Pulse-labelling experiments with growing Neurospora crassa revealed that the polypeptides composing the protein moiety of a cytochrome oxidase preparation are derived from at least four independent pools of precursor polypeptides. The pool sizes range from 2 ° f 0 to 25 °/0 of the amount of the corresponding polypeptide present in cytochrome oxidase. The smallest pool is assigned to a polypeptide of mitochondrial origm. Serial pools were found for one of the polypeptides.}, subject = {Biochemie}, language = {en} } @article{WeissSebaldSchwabetal.1973, author = {Weiss, H. and Sebald, Walter and Schwab, A. J. and Kleinow, W. and Lorenz, B.}, title = {Contribution of mitochondrial and cytoplasmic protein synthesis to the formation of cytochrome b and cytochrome aa\(_3\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62835}, year = {1973}, abstract = {A cytochrome b preparation from Neurospora crassa mitochondria is found to consist of three polypeptides (apparent molecular weight 10 000, 11 000 and 32 000), a cytochrome aa3 preparation of six to seven polypeptides (apparent molecular weight 8 000, 11 000, 13 000, 18 000, 28 000 and 36 000). Selective incorporation of radioactive amino acids by eilher mitochondrial protein synthesis when the cytoplasmic one is blocked or by the cytoplasmic protein synthesis, when the mitochondrial one is blocked, indicates that one cytochrome b polypeptide (mw 32 000) and one to three cytochrome aa3 polypeptides (mw 36 000, 28 000 and 18 000) are mitochondrial translation products, the other cytochrome b and cytochrome aa3 polypeptides cytoplasmic translation products. The delayed appearance of labeling in the cytochrome b and cytochrome aa3 polypeptides compared to the average cell protein after a pulse of <~H leueine revealed that these polypeptides are derived from separate pools of precursor polypeptides. The pool sizes range from 2 p. cent to 25 p. cent of the amount of the corresponding polypeptide present in the cytochromes. The 32 000 molecular weight polypeptide of cytochrome band at least the 18 000 molecular weight polypeptide of cytochrome aa\(_3\) are mitochondrial translation products as well in the fungus Neurospora crassa as in the insect Locusta migratoria. So, despite the fact that the size of mitochondrial DNA and mitochondrial ribosomes is reduced in insects, the products have maintained their characteristics.}, 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{JacklSebald1975, author = {Jackl, G. and Sebald, Walter}, title = {Identification of two products of mitochondrial protein synthesis associated with mitochondrial adenosine triphosphatase from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62812}, year = {1975}, abstract = {Soluble mitochondrial ATPase (F1) isolated from Neurospora crassa is resolved by dodecylsulfate- gel electrophoresis into five polypeptide bands with apparent molecular weights of 59000, 55000, 36000, 15000 and 12000. At least nine further polypeptides remain associated with ATPase after disintegration of mitochondria with Triton X-100 as shown by the analysis of an immunoprecipitate obtained with antiserum to F 1 A TPase. Two of the associated polypeptides with apparent molecular weights of 19000 and 11000 are translated on mitochondrial ribosomes, as demonstrated by incorporation in vivo of radioactive leueine in the presence of specific inhibitors of mitochondrial (chloramphenicol) and extramitochondrial ( cycloheximide) protein synthesis. The appearance of mitochondrial translation products in the immunoprecipitated A TPase complex is inhibited by' cycloheximide. The same applies for some of the extramitochondrial translation products in the presence of chloramphenicol. This suggests that both types of polypeptides are necessary for the assembly of the A TPase complex.}, subject = {Biochemie}, language = {en} } @article{GrafSebald1978, author = {Graf, T. and Sebald, Walter}, title = {The dicyclohexylcarbodiimide-binding protein of the mitochondrial ATPase complex from beef heart. Isolation and amino acid composition}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62806}, year = {1978}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{SebaldGrafLukins1979, author = {Sebald, Walter and Graf, T. and Lukins, H. B.}, title = {The dicyclohexylcarbodiimide-binding protein of the mitochondrial ATPase complex from Neurospora crassa and Saccharomyces cerevisiae. Identification and isolation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62792}, year = {1979}, abstract = {Incubation of mitochondria from Neuraspara crassa and Saccharomyces cerevisiae with the radioactive ATPase inhibitor [14C]dicyclohexylcarbodiimide results in the irreversible and rather specific labelling of a low-molecular-weight polypeptide. This dicyclohexylcarbodiimide-binding protein is identical with the smallest subunit (Mr 8000) of the mitochondrial ATPase complex, and it occurs as oligomer, probably as hexamer, in the enzyme protein. The dicyclohexylcarbodiimide-binding protein is extracted from whole mitochondria with neutral chloroformjmethanol both in the free and in the inhibitor-modified form. In Neuraspara and yeast, this extraction is highly selective and the protein is obtained in homogeneaus form when the mitochondria have been prewashed with certain organic solvents. The bound dicyclohexylcarbodiimide Iabel is enriched in the purified protein up to 50-fold compared to whole mitochondria. Based on the amino acid analysis, the dicyclohexylcarbodiimide-binding protein from Neurospora and yeast consists of at least 81 and 76 residues, respectively. The content of hydrophobic residues is extremely high. Histidine and tryptophan are absent. The N-terminal ~mino acid is tyrosine in Neuraspara and formylmethionine in yeast.}, subject = {Biochemie}, language = {en} } @article{MichelWachterSebald1979, author = {Michel, R. and Wachter, E. and Sebald, Walter}, title = {Synthesis of a larger precursor for the proteolipid subunit of the mitochondrial ATPase complex of Neurospora crassa in a cell-free wheat germ system}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62789}, year = {1979}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{SebaldWachterTzagoloff1979, author = {Sebald, Walter and Wachter, E. and Tzagoloff, A.}, title = {Identification of amino acid substitutions in the dicyclohexylcarbodiimide-binding subunit of the mitochondrial ATPase complex from oligomycin-resistant mutants of Saccharomyces cerevisiae}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62770}, year = {1979}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{HoppeSchairerSebald1980, author = {Hoppe, J. and Schairer, H. U. and Sebald, Walter}, title = {The proteolipid of a mutant ATPase from Escherichia coli defective in H\(^+\)-conduction contains a glycine instead of the carbodiimide-reactive aspartyl residue}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62769}, year = {1980}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{HoppeSebald1980, author = {Hoppe, J. and Sebald, Walter}, title = {Amino acid sequence of the proteolipid subunit of the proton-translocating ATPase complex from the thermophilic bacterium PS-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62754}, year = {1980}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{ViebrockPerzSebald1982, author = {Viebrock, A. and Perz, A. and Sebald, Walter}, title = {The imported preprotein of the proteolipid subunit of the mitochondrial ATP synthase from Neurospora crassa. Molecular cloning and sequencing of the mRNA}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62742}, year = {1982}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{SebaldFriedlSchaireretal.1982, author = {Sebald, Walter and Friedl, P. and Schairer, H. U. and Hoppe, J.}, title = {Structure and genetics of the H\(^+\)-conducting F\(_0\) portion of the ATP synthase}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62733}, year = {1982}, abstract = {The ATP synthase occurs in remarkably conserved form in procaryotic and eucaryotic cells. Thus, our present knowledge of ATP synthase is derived from sturlies of the enzyme from different organisms, each affering specific experimental possibilities. In recent tim es, research on the H\(^+\) -conducting F0 part of the ATP synthase has been greatly stimulated by two developments in the Escherichio coli system. Firstly, the purification and reconstitution of the whole ATP synthase as weil as the proton conductor Fa from E. coli have been achieved. These functionally active preparations are well defined in terms of subunit composition, similar to the thermophilic enzyme from PS-3 studied by Kagawa's group.u Secondly, the genetics and the molecular cloning of the genes of all the F\(_0\) subunits from E. coli yielded information on the function of subunit polypeptides and essential amino acid residues. Furthermore, the amino acid sequence of hydrophobic F\(_0\) subunits, which are difficult to analyze by protein-chemical techniques, could be derived from the nucleotide sequence of the genes. These achievements, which shall be briefly summarized in the next part of this communication, provide the framework to study specific aspects of the structure and function of the F\(_0\) subunits.}, subject = {Biochemie}, language = {en} } @article{SchairerHoppeSebaldetal.1982, author = {Schairer, H. U. and Hoppe, J. and Sebald, Walter and Friedl, P.}, title = {Topological and functional aspects of the proton conductor, F\(_0\), of the Escherichia coli ATP-synthase}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62721}, year = {1982}, abstract = {The isolated H\(^+\) conductor, F\(_0\) , of the Escherichia co1i ATP-synthase consists of three subunits, a, b, and c. H\(^+\) -permeable liposomes can be reconstit~ted with F\(_0\) and lipids; addition of F\(_1\)-ATPase reconstitutes a functional ATP-synthase. Mutants with altered or misslng F\(_0\) subunits are defective in H\(^+\) conduction. Thus, all three subunits are necessary for the expression of H\(^+\) conduction. The subunits a and b contain binding sites for F\(_1\)• Computer calculations, cross-links, membrane-permeating photo-reactive labels, and proteases were used to develop tentative structural models for the individual F\(_0\) subunits.}, subject = {Biochemie}, language = {en} } @article{HoppeFriedlSchaireretal.1983, author = {Hoppe, J. and Friedl, P. and Schairer, H. U. and Sebald, Walter and Meyenburg, K. von and Jorgensen, B. B.}, title = {The topology of the proton translocating F\(_0\) component of the ATP synthase from E. coli K12: studies with proteases}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62718}, year = {1983}, abstract = {The accessibility of the three F\(_0\) subunits a, b and c from the Escherichia coli Kll A TP synthase to various proteases was studied in F\(_1\)-depleted inverted membrane vesicles. Subunit b was very sensitive to all applied proteases. Chymotrypsin produced a defined fragment of mol. wt. 1S 000 which remained tightly bound to the membrane. The cleavage site was located at the C-terminal region of subunit b. Larger amounts of proteases were necessary to attack subunit a (mol. wt. 30 000). There was no detectable deavage of subunit c. It is suggested that the major hydrophilic part of subunit b extends from the membrane into the cytoplasm and is in contact with the F\(_1\) sector. The F\(_1\) sector was found to afford some protection against proteolysis oftheb subunit in vitro andin vivo. Protease digestion bad no influence on the electro-impelled H\(^+\) conduction via F\(_0\) bot ATP-dependent H\(^+\) translocation could not be reconstituted upon binding of F\(_1\)• A possible role for subunit b as a linker between catalytic events on the F\(_1\) component and the proton pathway across the membrane is discussed.}, subject = {Biochemie}, language = {en} } @article{VeloursEsparzaHoppeetal.1984, author = {Velours, J. and Esparza, M. and Hoppe, J. and Sebald, Walter and Guerin, B.}, title = {Amino acid sequence of a new mitochondrially synthesized proteolipid of the ATP synthase of Saccharomyces cerevisiae}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62695}, year = {1984}, abstract = {The purification and the amino acid sequence of a proteolipid translated on ribosomes in yeast mitochondria is reported. This protein, which is a subunit of the A TP synthase, was purified by extraction with chloroform/methanol (2/1) and subsequent chromatography on phosphocellulose and reverse phase h.p.l.c. A mol. wt. of 5500 was estimated by chromatography on Bio-Gel P-30 in 8011/o fonnie acid. The complete amino acid sequence of this protein was determined by automated solid phase Edman degradation of the whole protein and of fragments obtained after cleavage with cyanogen bromide. The sequence analysis indicates a length of 48 amino acid residues. The calculated mol. wt. of 5870 corresponds to the value found by gel chromatography. This polypeptide contains three basic residues and no negatively charged side chain. The three basic residues are clustered at the C terminus. The primary structure of this protein is in full agreement with the predicted amino acid sequence of the putative polypeptide encoded by the mitochondrial aap1 gene recently discovered in Saccharomyces cerevisiae. Moreover, this protein shows 5011/o homology with the amino acid sequence of a putative polypeptide encoded by an unidentified reading frame also discovered near the mitochondrial ATPase subunit 6 genein Aspergillus nidulans.}, subject = {Biochemie}, 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{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} }