266 resultados para Nissen
Resumo:
von Georg Nikolaus von Nissen. Nach dessen Tode hrsg. von Constanze, Wittwe von Nissen, früher Wittwe Mozart
Resumo:
von Georg Nikolaus von Nissen. Nach dessen Tode hrsg. von Constanze, Wittwe von Nissen, früher Wittwe von Mozart
Resumo:
Von Fr. Nissen
Resumo:
Von Fr. Nissen
Resumo:
Von Friedr. Nissen
Resumo:
A technique for systematic peptide variation by a combination of rational and evolutionary approaches is presented. The design scheme consists of five consecutive steps: (i) identification of a “seed peptide” with a desired activity, (ii) generation of variants selected from a physicochemical space around the seed peptide, (iii) synthesis and testing of this biased library, (iv) modeling of a quantitative sequence-activity relationship by an artificial neural network, and (v) de novo design by a computer-based evolutionary search in sequence space using the trained neural network as the fitness function. This strategy was successfully applied to the identification of novel peptides that fully prevent the positive chronotropic effect of anti-β1-adrenoreceptor autoantibodies from the serum of patients with dilated cardiomyopathy. The seed peptide, comprising 10 residues, was derived by epitope mapping from an extracellular loop of human β1-adrenoreceptor. A set of 90 peptides was synthesized and tested to provide training data for neural network development. De novo design revealed peptides with desired activities that do not match the seed peptide sequence. These results demonstrate that computer-based evolutionary searches can generate novel peptides with substantial biological activity.
Resumo:
The A loop is an essential RNA component of the ribosome peptidyltransferase center that directly interacts with aminoacyl (A)-site tRNA. The A loop is highly conserved and contains a ubiquitous 2′-O-methyl ribose modification at position U2552. Here, we present the solution structure of a modified and unmodified A-loop RNA to define both the A-loop fold and the structural impact of the U2552 modification. Solution data reveal that the A-loop RNA has a compact structure that includes a noncanonical base pair between C2556 and U2552. NMR evidence is presented that the N3 position of C2556 has a shifted pKa and that protonation at C2556-N3 changes the C-U pair geometry. Our data indicate that U2552 methylation modifies the A-loop fold, in particular the dynamics and position of residues C2556 and U2555. We compare our structural data with the structure of the A loop observed in a recent 50S crystal structure [Ban, N., Nissen, P., Hansen, J., Moore, P. B. & Steitz, T. A. (2000) Science 289, 905–920; Nissen, P., Hansen, J., Ban, N., Moore, P. B. & Steitz, T. A. (2000) Science 289, 920–930]. The solution and crystal structures of the A loop are dramatically different, suggesting that a structural rearrangement of the A loop must occur on docking into the peptidyltransferase center. Possible roles of this docking event, the shifted pKa of C2556 and the U2552 2′-O-methylation in the mechanism of translation, are discussed.
Resumo:
Analysis of the 2.4-Å resolution crystal structure of the large ribosomal subunit from Haloarcula marismortui reveals the existence of an abundant and ubiquitous structural motif that stabilizes RNA tertiary and quaternary structures. This motif is termed the A-minor motif, because it involves the insertion of the smooth, minor groove edges of adenines into the minor groove of neighboring helices, preferentially at C-G base pairs, where they form hydrogen bonds with one or both of the 2′ OHs of those pairs. A-minor motifs stabilize contacts between RNA helices, interactions between loops and helices, and the conformations of junctions and tight turns. The interactions between the 3′ terminal adenine of tRNAs bound in either the A site or the P site with 23S rRNA are examples of functionally significant A-minor interactions. The A-minor motif is by far the most abundant tertiary structure interaction in the large ribosomal subunit; 186 adenines in 23S and 5S rRNA participate, 68 of which are conserved. It may prove to be the universally most important long-range interaction in large RNA structures.
Resumo:
Front Row: Maggie Busch, Lexi Zimmerman, Veronica Rood, Kerry Hance, Stesha Selsky, Liz Raschke, Jackie Nissen.
Back Row: Cassie Petoskey, Katie Bruzdzinski, Karlee Bruck, Sarah Draves, Lyndsay Miller, Beth Karpiak, Megan Bower.
Resumo:
Back Row: Veronica Rood, Beth Karpiak, Claire McElheny, Courtney Fletcher, Karlee Bruck, Megan Bower,
Middle row: Alex Hunt, Juliana Paz, Sloane Donhoff, Lexi Zimmerman, Jackie Nissen, Cassie Petoskey
Front Row: Maggie Busch, Kerry Hance, Michelle McMahon
Resumo:
Top Row” Lexi Zimmerman, Sloane Donhoff, Maggie Brusch
Third Row: Catherine Yager, Claire McElheny, Courtney Fletcher, Karlee Bruck, Cassie Petoskey,
Second Row: Wil Turner (trainer) Amanda Ault (assistant coach) Erin More (dir. VB oper.) Megan Bower, Alex Hunt, Veronica Rood, Juliana Paz, Mark Rosen (head coach), Leisa Rosen (associate head coach)
Front Row: Amanda Yerke, Michelle McMahon, Jackie Nissen
Resumo:
Mode of access: Internet.
Resumo:
National Highway Traffic Safety Administration, Washington, D.C.