TY  - JOUR
A1  - Barnekow, Angelika
A1  - Gessler, Manfred
T1  - Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro
N2  - Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60<sup>c-src</sup> tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60<sup>c-src</sup> kinase.
KW  - Biochemie
KW  - c-src
KW  - differentiation
KW  - protein tyrosine kinase
KW  - protooncogene
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59278
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Bruns, Gail A. P.
T1  - Molecular mapping and cloning of the breakpoints of a chromosome 11p14.1-p13 deletion associated with the AGR syndrome
N2  - Chromosome 11p13 is frequently rearranged in individuals with the WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) or parts of this syndrome. To map the cytogenetic aberrations molecularly, we screened DNA from cell Unes with known WAGR-related chromosome abnormalities for rearrangements with pulsed fleld gel (PFG) analysis using probes deleted from one chromosome 11 homolog of a WAGR patient. The first alteration was detected in a cell line from an individual with aniridia, genitourinary anomalies, mental retardation, and a deletion described as 11p14.1-p13. We have located one breakpoint close to probe HU11-164B and we have cloned both breakpoint sites as well as the junctional fragment. The breakpoints subdivide current intervals on the genetic map, and the probes for both sides will serve as important additional markers for a long-range restriction map of this region. Further characterization and sequencing of the breakpoints may yield insight into the mechanisms by which these deletions occur.
KW  - Biochemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59264
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Thomas, G. H.
A1  - Couillin, P.
A1  - Junien, C.
A1  - McGillivray, B. C.
A1  - Hayden, M.
A1  - Jaschek, G.
A1  - Bruns, G. A.
T1  - A deletion map of the WAGR region on chromosome II
N2  - The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals. We have utilized 31 DNA probes which map to the WAGR deletion region, together with six reference loci and 13 WAGR-related deletions, to subdivide this area into 16 intervals. Specific intervals have been correlated with phenotypic features, leading to the identification of individual subregions for the aniridia and Wilms tumor loci. Delineation, by specific probes, of multiple intervals above and below the critical region and of five intervals within the overlap area provides a framework map for molecular characterization of WAGR gene loci and of deletion boundary regions.
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59255
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Bruns, G. A. P.
T1  - A physical map around the WAGR complex on the short arm of chromosome 11
N2  - A long-range restriction map of part of the short arm of ehromosome 11 including the WAGR region has been constructed using pulsed-field gel electrophoresis and a number of infrequently cutting restriction enzymes. A total of 15.4 Mbp has been mapped in detall, extending from proximal 11p14 to the distal part of 11p12. The map localizes 35 different DNA probes and reveals at least nine areas with features eharaeteristle of BTF islands, some of which may be candidates for the different loci underlying the phenotype of the WAGR syndrome. This map will furthermore allow screening of DNA from individuals with WAGR-related phenotypes and from Wilms tumors for associated chromosomal rearrangements.
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59246
ER  - 
TY  - JOUR
A1  - van Heyningen, V.
A1  - Bickmore, W. A.
A1  - Seawright, A.
A1  - Fletcher, J. M.
A1  - Maule, J.
A1  - Fekete, G.
A1  - Gessler, Manfred
A1  - Bruns, G. A.
A1  - Huerre-Jeanpierre, C.
A1  - Junien, C.
T1  - Role for the Wilms tumor gene in genital development?
N2  - No abstract available
KW  - Biochemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59238
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Hameister, H.
A1  - Henry, I.
A1  - Junien, C.
A1  - Braun, T.
A1  - Arnold, H. H.
T1  - The human MyoD1 (MYF3) gene maps on the short arm of chromosome 11 but is not associated with the WAGR locus or the region for the Beckwith-Wiedemann syndrome
N2  - The human gene encoding the myogenic determination factor myf3 (mouse MyoD1) has been mapped to the short arm of chromosome 11. Analysis of several somatic cell hybrids containing various derivatives with deletions or translocations revealed that the human MyoD (MYF3) gene is not associated with the WAGR locus at chromosomal band 11pl3 nor with the loss of the heterozygosity region at 11p15.5 related to the Beckwith-Wiedemann syndrome. Subregional mapping by in situ hybridization with an myf3 specific probe shows that the gene resides at the chromosomal band llp14, possibly at llp14.3.
KW  - Biochemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59221
ER  - 
TY  - JOUR
A1  - Vortkamp, A.
A1  - Thias, U.
A1  - Gessler, Manfred
A1  - Rosenkranz, W.
A1  - Kroisel, P. M.
A1  - Tommerup, N.
A1  - Kruger, G.
A1  - Gotz, J.
A1  - Pelz, L.
A1  - Grzeschik, Karl-Heinz
T1  - A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p
N2  - No abstract available
KW  - Biochemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59217
ER  - 
TY  - JOUR
A1  - Wolf, Markus
A1  - Klug, Jörg
A1  - Hackenberg, Reinhard
A1  - Gessler, Manfred
A1  - Grzeschik, Karl-Heinz
A1  - Beato, Miguel
A1  - Suske, Guntram
T1  - Human CC10, the homologue of rabbit uteroglobin: genomic cloning, chromosomal localization and expression in endometrial cell lines
N2  - No abstract available
KW  - Biochemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59206
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - König, A.
A1  - Bruns, G. A. P.
T1  - The genomic organization and expression of the WT1 gene
N2  - The Wilms tumor gene WTl, a proposed tumor suppressor gene, has been identifled based on its location within a homozygous deletion found in tumor tissue. The gene encodes a putative transcription factor containing a Cys/His zinc finger domain. The critical homozygous deletions, however, are rarely seen, suggesting that in many cases the gene may be inactivated by more subtle alterations. To facilitate the seareh for smaller deletions and point mutations we have established the genomic organization of the WTl gene and have determined the sequence of all 10 exons and flanking intron DNA. The pattern of alternative splicing in two regions has been characterized in detail. These results will form the basis for future studies of mutant alleles at this locus.
KW  - Biochemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59195
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Grupe, Andrew
A1  - Grzeschik, Karl-Heinz
A1  - Pongs, Olaf
T1  - The potassium channel gene HK1 maps to human chromosome 11p14.1, close to the FSHB gene
N2  - Transiently activating (A-type) potassium (K) channels are important regulators of action potential and action potential firing frequencies. HK1 designates the firsthuman cDNA that is highly homologous to the rat RCK4 cDNA that codes for an A-type K-channel. The HK1 channel is expressed in heart. By somatic cell hybrid analysis, the HK1 gene has been assigned to human chromosome 11p13-pl4, the WAGR deletion region (Wilms tumor, aniridia, genito-urinary abnormalities and mental retardation). Subsequent pulsed field gel (PFG) analysis and comparison with the well-established PFG map of this region localized the gene to 11p14, 200-600 kb telomeric to the FSHB gene.
KW  - Biochemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59184
ER  - 
TY  - JOUR
A1  - Poulat, F.
A1  - Morin, D.
A1  - Konig, A.
A1  - Brun, P.
A1  - Giltay, J.
A1  - Sultan, C.
A1  - Dumas, R.
A1  - Gessler, Manfred
A1  - Berta, P.
T1  - Distinct molecular origins for Denys-Drash and Frasier syndromes
N2  - The direct involvment of the Wilm's tumor suppressor gene (WTl) in Denys-Drash syndrome through mutations within exons 8 or 9 has recently been established. The absence of such alterations in three patients with Frasier syndrome provides a molecular basis for distinguishing these two syndromes that are associated with streak gonads, pseudohermaphroditism and renal failure.
KW  - Biochemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59172
ER  - 
TY  - JOUR
A1  - Konig, Anja
A1  - Jakubiczka, Sybille
A1  - Wieacker, Peter
A1  - Schlösser, Hans W.
A1  - Gessler, Manfred
T1  - Further evidence that imbalance of WT1 isoforms may be involved in Denys-Drash syndrome
N2  - No abstract available
KW  - Biochemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59167
ER  - 
TY  - JOUR
A1  - Henry, Isabelle
A1  - Hoovers, Jan
A1  - Barichard, Fernande
A1  - Berthéas, Marie-Francoise
A1  - Puech, Anne
A1  - Prieur, Fabienne
A1  - Gessler, Manfred
A1  - Bruns, Gail
A1  - Mannens, Marcel
A1  - Junien, Claudine
T1  - Pericentric intrachromosomal insertion responsible for recurrence of del(11)(p13p14) in a family
N2  - The combined use of qualitative and quantitative analysis of I I p I 3 polymorphic markers tagether with chromosomal in situ suppression hybridization (CISS) with biotin labeled probes mapping to I I p allowed us to characterize a complex rearrangement segregating in a family. We detected a pericentric intrachromosomal insertion responsible (or recurrence of del( I I )(p 13p 14) in the family: an insertion of band I I p 13-p 14 carrying the genes for predisposition to Wilms' tumor, WT I, and for aniridia, AN2, into the long arm of chromosome I I in II q 13-q 1<4. Asymptomatic balanced carriers were observed over three generations. Classical cytogenetics had failed to detect this anomaly in the balanced carriers, who were first considered to be somatic mosaics for del( II )(p 13). Two of these women gave birth to children carrying a deleted chromosome II. most likely resulting from the loss of the I I p 13 band inserted in I I q. Although in both cases the deletion encompassed exactly the same maternally inherited markers, there was a wide Variation in clinical expression. One child, with the karyotype 46,XY,del(ll)(pllpl4), presented the full-blown WAGR syndrome with anlridia, mental retardation, Wilms' tumor, and pseudohermaphroditism, but also had proteinuria and glomerular sclerosis reminiscent of Drash syndrome. In contrast, the other one, a girl with the karyotype 46,XX,del( I I )(p I 3), only had aniridia. Although a specific set of mutational sites has been observed in Drash patients, these findings suggest that the loss of one copy of the WTI gene can result in similar genital and kidney abnormalities.
KW  - Biochemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59157
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Konig, Anja
A1  - Moore, Jay
A1  - Qualman, Steven
A1  - Arden, Karen
A1  - Cavenee, Webster
A1  - Bruns, Gail
T1  - Homozygous inactivation of WTI in a Wilms' tumor associated with the WAGR syndrome
N2  - Wilms' tumor is a childhood nephroblastoma that is postulated to arise through the inactivation of a tumor suppressor gene by a two-hit mechanism. A candidate II p 13 Wilms' tumor gene, WTI, has been cloned and shown to encode a zinc finger protein. Patients with the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities, and mental retardation) have a high risk of developing Wilms' tumor and they carry constitutional deletions of one chromosome II allele encompassing the WTI gene. Analysis of the remaining WTI allele in a Wilms' tumor from a WAGR patient revealed the deletion of a single nucleotide in exon 7. This mutation likely played a key role in tumor formation, as it prevents translation of the DNA-binding zinc finger domain that is essential for the function of the WTI polypeptide as a transcriptional regulator.
KW  - Biochemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59146
ER  - 
TY  - JOUR
A1  - Schwarz, Klaus
A1  - Hameister, Horst
A1  - Gessler, Manfred
A1  - Grzeschik, Karl-Heinz
A1  - Hansen-Hagge, Thomas E.
A1  - Bartram, Claus R.
T1  - Confirmation of the localization of the human recombination activating gene 1 (RAG1) to chromosome 11p13
N2  - The human recombination activating gene 1 (RAGl) has previously been mapped to chromosomes 14q and 11 p. Here we confirm the chromosome 11 assignment by two independent approaches: autoradiographic and fluorescence in situ hybridization to metaphase spreads and analysis of human-hamster somatic cell hybrid DNA by the polymerase chain reaction (PCR) and Southern blotting. Our results unequivocally localize RAG1 to llp13.
KW  - Biochemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59136
ER  - 
TY  - JOUR
A1  - Schwartz, Faina
A1  - Neve, Rachel
A1  - Eisenman, Robert
A1  - Gessler, Manfred
A1  - Bruns, Gail
T1  - A WAGR region gene between PAX-6 and FSHB expressed in fetal brain
N2  - Developmental delay or mental retardation is a frequent component of multi-system anomaly syndromes associated with chromosomal deletions. Isolation of genes involved in the mental dysfunction in these disorders should define loci important in brain formation or function. We have identified a highly conserved locus in the distal part of 11 p 13 that is prominently expressed in fetal brain. Minimal expression is observed in a number of other fetal tissues. The gene maps distal to PAX-6 but proximal to the loci for brain-derived neurotrophic factor (BDNF) and the beta subunit of follicle stimulating hormone (FSHB), within a region previously implicated in the mental retardation component of some WAGR syndrome patients. Within fetal brain, the corresponding transcript is prominent in frontal, motor and primary visual cortex as weil as in the caudate-putamen. The characteristics of this gene, including the striking evolutionary conservation at the locus, suggest that the encoded protein may function in brain development.
KW  - Biochemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59125
ER  - 
TY  - JOUR
A1  - Tzagoloff, A.
A1  - Macino, G.
A1  - Sebald, Walter
T1  - Mitochondrial genes and translation products
N2  - No abstract available
KW  - Biochemie
Y1  - 1979
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47408
ER  - 
TY  - JOUR
A1  - von Jagow, Gerhard
A1  - Sebald, Walter
T1  - b-Type cytochromes
N2  - No abstract available
KW  - Biochemie
Y1  - 1980
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47383
ER  - 
TY  - JOUR
A1  - Hoppe, J.
A1  - Schairer, HU
A1  - Sebald, Walter
T1  - Identification of amino-acid substitutions in the proteolipid subunit of the ATP synthase from dicyclohexylcarbodiimide-resistant mutants of Escherichia coli
N2  - The amino acid sequence of the proteolipid subunit of the A TP synthase was analyzed in six mutant strains from Escherichia coli K 12, selected for their increased resistance towards the inhibitor N,N'-dicyclohexylcarbodiimide. All six inhibitor-resistant mutants were found to be altered at the same position of the proteolipid, namely at the isoleucine at residue 28. Two substitutions could be identified. In type I this residue was substituted by a valine resulting in a moderate decrease in sensitivity to dicyclohexylcarbodiimide. Type II contained a threonine residue at this position. Here a strong resistance was observed. These two amino acid substitutions did not influence functional properties of the ATPase complex. ATPase as well as A TP-dependent proton-translocating activities of mutant membranes were indistinguishable from the wild type. At elevated concentrations, dicyclohexylcarbodiimide still bound specifically to the aspartic acid at residue 61 of the mutant proteolipid as in the wild type, and thereby inhibited the activity of the ATPase complex. It is suggested that the residue 28 substituted in the resistant mutants interacts with dicyclohexylcarbodiimide during the reactions leading to the covalent attachment of the inhibitor to the aspartic acid at residue 61. This could indicate that these two residues are in close vicinity and would thus provide a first hint on the functional conformation of the proteolipid. Its polypeptide chain would have to fold back to bring together these two residues separated by a segment of 32 residues.
KW  - Biochemie
Y1  - 1980
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47374
ER  - 
TY  - JOUR
A1  - Sebald, Walter
T1  - Biogenesis of mitochondrial ATPase
N2  - No abstract available
KW  - Biochemie
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47362
ER  - 
TY  - THES
A1  - Kraich, Michael
T1  - Strukturelle und funktionelle Untersuchungen der Interaktion zwischen Ligand und Rezeptor im Interleukin-4- und Interleukin-13-System
T1  - Structural and functional studies of the interaction between ligand and receptor in the interleukin-4 and interleukin-13 system
N2  - Interleukin-4 (IL-4) und Interleukin-13 (IL-13) sind bedeutende Regulatorproteine des Immunsystems. Sie spielen eine entscheidende Rolle bei der Entstehung und dem Verlauf von allergischen Erkrankungen, wie z.B. Asthma. Um ihre Signale in die Zielzelle zu transduzieren, kann von beiden Zytokinen der gleiche Zelloberflächenrezeptor verwendet werden, wodurch sich die überlappenden, biologischen Funktionen erklären lassen. Dieser gemeinsam genutzte Rezeptor ist aus den beiden Untereinheiten IL-4Ralpha; und IL-13Ralpha1 aufgebaut. Da IL-4 und IL-13 auf Aminosäureebene nur etwa 25% Sequenzidentität besitzen und stark unterschiedliche Affinitäten zu den beiden Rezeptorketten besitzen, stellt sich die Frage, durch welchen molekularen Erkennungsmechanismus, die Affinität und die Spezifität der Ligand-Rezeptor-Interaktion unabhängig voneinander reguliert werden kann. In dieser Arbeit gelang es, rekombinante Expressions- und Aufreinigungsstrategien für IL-13 und die extrazellulären Domänen der Rezeptorketten IL-13Ralpha1 und IL-13Ralpha2 zu entwickeln. Dadurch war es mögliche, eine breite Mutations-/Interaktionsanalyse der IL-13Ralpha1-Kette durchzuführen.Es konnte gezeigt werden, dass die N-terminale FnIII-ähnliche Domäne von IL-13Ralpha1 sowohl an der Bindung von IL-13 als auch an der Interaktion mit IL-4 beteiligt ist. Im funktionellen Bindeepitop der IL-13Ralpha1-Kette wurden die Aminosäurereste Arg84, Phe253 und Tyr321 als Hauptbindungsdeterminanten für die Interaktion mit IL-13 identifiziert. Durch die Interaktionsstudien der IL-13Ralpha1-Varianten mit IL-4 wurde gezeigt, dass diese Hauptbindungsdeterminanten auch für die niederaffine Bindung von IL-4 von größter Bedeutung sind. Die funktionellen Bindeepitope für IL-4 und IL-13 auf der IL-13Ralpha1-Kette sind nahezu identisch und überlappen in einem großen Bereich. Aufgrund der Ergebnisse aus der Mutagenesestudie war es möglich, ein Strukturmodell der extrazellulären Domäne der IL-13Ralpha1-Kette zu erstellen. Darin wird eine neuartige Orientierung der N-terminalen FnIII-Domäne und deren Beteiligung an der Ligandeninteraktion dargestellt. Mit Hilfe des Strukturmodells gelang es, neue Aminosäurerest auf der Oberfläche von IL-13 zu identifizieren, die an der Bindung zu IL-13Ralpha1 beteiligt sind, was die Relevanz des Strukturmodells weiter unterstreicht. In einem weiteren Teil dieser Arbeit wurde versucht, den molekularen Mechanismus aufzuklären, durch den es den superagonistischen IL-4-Varianten T13D und F82D gelingt, mit dreifach höherer Affinität an die IL-4Ralpha-Kette zu binden, als wildtypischer Ligand. Durch strukturelle und funktionelle Untersuchungen wurde gezeigt, dass der Affinitätssteigerung ein indirekter Mechanismus zugrunde liegt, bei dem eine Konformationsänderung und die Fixierung der Arg85-Seitenkette von IL-4 zur Ausbildung von zusätzlichen Ligand-Rezeptor-Interaktionen führt. Das Bindeepitop zwischen IL-4 und der IL-4Ralpha-Kette besitzt eine modulare Architektur aus drei unabhängig voneinander agierenden Interaktionsclustern. Bei der Interaktion von wildtypischem IL-4 mit IL-4Ralpha tragen nur zwei dieser Cluster in signifikanter Weise zur freien Bindeenergie bei. Im Falle der superagonistischen IL-4-Varianten ist jedoch auch das dritte Cluster an der Generierung von zusätzlicher, freier Bindeenergie beteiligt, wodurch die Affinität zwischen Ligand und Rezeptor erhöht wird. Damit stellt der modulare Aufbau der Interaktionsfläche zwischen IL-4 und der IL-4Ralpha-Kette möglicherweise einen Mechanismus dar, über den Proteine die Affinität von Wechselwirkungen über einen großen Bereicht variieren können, ohne dabei Spezifität einzubüssen. Da IL-4 und IL-13 als interessante Zielmoleküle für die Therapie von allergischen und asthmatischen Erkrankungen erkannt worden sind, können die in der vorliegenden Arbeit gewonnenen Informationen über den Bindemechanismus und die Einblicke in den molekularen Charakter der Interaktion zwischen den beiden Zytokinen und ihren spezifischen Rezeptorketten dabei helfen, neuartige und hoch spezifische, inhibitorische Moleküle zu entwickeln.
N2  - Interleukin-4 (IL-4) and Interleukin-13 (IL-13) are important regulatory proteins of the immune system. They play a key role in the development and the progression of allergic diseases like asthma. For signal transduction into the target cell, both cytokines can use an identical cell surface receptor, which is an explanation for many overlapping biological functions of IL-4 and IL-13. This common receptor consists of the two subunits IL-4Ralpha and IL-13Ralpha1. Because IL-4 and IL-13 share only 25% sequence identity on the amino acid sequence level and because they show very different affinities to the two receptor chains, the question has to be raised, by which molecular recognition mechanism it is possible to regulate affinity and specificity of the ligand-receptor-interaction independently. In the course of this work recombinant expression and purification strategies for IL-13 and the extracellular domains of IL-13Ralpha1 and IL-13Ralpha2 were established. Therefore it was possible to perform a broad mutagenesis and interaction analysis of the IL-13Ralpha1 chain. It was shown, that the N-terminal FnIII-like domain of IL-13Ralpha1 participates in the binding of IL-13 as well as in the interaction with IL-4. As part of the functional epitope the amino acid residues Arg84, Phe253 and Tyr321 were identified to be main binding determinants for the interaction with IL-13. By carrying out interaction studies with IL-4 it could be demonstrated, that the same residues are also from great importance for the low affinity binding of IL-4. The functional epitopes for the binding of IL-4 and IL-13 are almost identical and are overlapping in a large area. Due to the results of the mutagenesis study it was possible to generate a structural model of the extracellular domain of the IL-13Ralpha1 chain. A key feature of this model is the novel orientation of the N-terminal FnIII-like domain and its involvement in ligand binding. According to the modelled structure new residues in IL-13 could be identified, that participate in the interaction with the IL-13Ralpha1. This further underlines the relevance of the shown structural model of the extracellulardomain of the IL-13Ralpha1 chain. In a different part of this work it was tried to elucidate the molecular mechanism, which enables the super-agonistic IL-4 variants T13D and F82D bind IL-4Ralpha with three times higher affinity than wildtype IL-4. With the help of structural und functional analysis it could be shown, that an indirect mechanism leads to the gain of affinity. A conformational change in and the fixation of the Arg85 side chain in IL-4 result in the formation of additional interactions between ligand and receptor. The binding interface between IL-4 and IL-4Ralpha exhibits a modular architecture consisting of three independently acting interaction clusters. For the binding of wild-type IL-4 to the IL-4Ralpha chain only two of the three clusters contribute a significant amount to the overall free binding energy. In the case of the super-agonistic IL-4 variants all three interaction clusters are used to generate additional free binding energy and to increase the affinity between ligand and receptor. Therefore the modular design of the IL-4/IL-4Ralpha interaction interface probably represents a mechanism, which enables proteins to alter the affinity of interactions over a broad range without loosing specificity. Because IL-4 and IL-13 were discovered as promising targets for the therapy of allergic and asthmatic diseases, the acquired information about the binding mechanism and the molecular characteristics of the interaction between the cytokines IL-4 and IL-13 and their specific receptor chains may help to design novel and highly specific inhibitory molecules.
KW  - Renaturierung <Biochemie>
KW  - Ligand <Biochemie>
KW  - Biochemie
KW  - Interleukin 4
KW  - Interleukin 13
KW  - Interaktion
KW  - Rezeptor
KW  - Immunologie
KW  - Allergie
KW  - Allerg
KW  - Proteinbiochemie
KW  - BIAcore
KW  - Oberflächenplasmonresonanz (SPR)
KW  - Strukturbiologie
KW  - interleukin-4
KW  - interleukin-13
KW  - protein interaction
KW  - BIAcore
KW  - structural biology
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-27655
ER  -