Preparation of 1'-C Deuterated Synthons for RNA Synthesis by H-Phosphonate Method Aiming at Two-Dimensional NMR Secondary Structure Studies

1996 ◽  
Vol 61 (3) ◽  
pp. 389-403 ◽  
Author(s):  
Luboš Arnold ◽  
Martina Pressová ◽  
David Šaman ◽  
Martin Vogtherr ◽  
Stefan Limmer
Keyword(s):  
Secondary Structure ◽  
Rna Synthesis ◽  
2D Nmr ◽  
Two Dimensional ◽  
Deuterium Incorporation ◽  
Spectral Pattern ◽  
Step Procedure ◽  
Noesy Spectra

1'-C Deuterated H-phosphonate synthons were prepared via a 12-step procedure starting from [1'-2H]ribose. The procedure included nucleosidation of 1'-O-acetyl-2',3',5'-O-tribenzoyl[1'-2H]ribose with appropriately protected nucleobases and preparation of nucleoside-H-phosphonates by slightly modified described procedures. The automated RNA synthesis of 5'-G*C*U*A*U*UUAU-3' and 3'-AC*G*A*U*A*AAGU-5' was performed on a Gene Assembler Plus DNA-synthesizer. These specifically deuterated oligoribonucleotides were subsequently compared with the corresponding non-deuterated sequences using 2D-NMR NOESY spectra. Specific deuterium incorporation resulted in the expected simplification of spectral pattern.

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

scholarly journals Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

2004 ◽  
Vol 126 (25) ◽  
pp. 7981-7990 ◽  
Author(s):  
Nurettin Demirdöven ◽  
Christopher M. Cheatum ◽  
Hoi Sung Chung ◽  
Munira Khalil ◽  
Jasper Knoester ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Secondary Structure ◽  
Two Dimensional ◽  
Two Dimensional Infrared Spectroscopy ◽  
Β Sheet

scholarly journals Secondary structure and hydrogen bonding of crambin in solution A two-dimensional NMR study

1988 ◽  
Vol 171 (1-2) ◽  
pp. 307-312 ◽  
Author(s):  
Rudolf M. J. N. LAMERICHS ◽  
Lawrence J. BERLINER ◽  
Rolf BOELENS ◽  
Antonio MARCO ◽  
Miguel LLINAS ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Secondary Structure ◽  
Two Dimensional ◽  
Nmr Study

scholarly journals Modification of the 5′ Terminus of Sindbis Virus Genomic RNA Allows nsP4 RNA Polymerases with Nonaromatic Amino Acids at the N Terminus To Function in RNA Replication

2003 ◽  
Vol 77 (4) ◽  
pp. 2301-2309 ◽  
Author(s):  
Yukio Shirako ◽  
Ellen G. Strauss ◽  
James H. Strauss
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Sindbis Virus ◽  
Rna Synthesis ◽  
Wild Type Virus ◽  
Progeny Virus ◽  
Minus Strand ◽  
Genomic Rna ◽  
Wild Type ◽  
N Terminus

ABSTRACT We have previously shown that Sindbis virus RNA polymerase requires an N-terminal aromatic amino acid or histidine for wild-type or pseudo-wild-type function; mutant viruses with a nonaromatic amino acid at the N terminus of the polymerase, but which are otherwise wild type, are unable to produce progeny viruses and will not form a plaque at any temperature tested. We now show that such mutant polymerases can function to produce progeny virus sufficient to form plaques at both 30 and 40°C upon addition of AU, AUA, or AUU to the 5′ terminus of the genomic RNA or upon substitution of A for U as the third nucleotide of the genome. These results are consistent with the hypothesis that (i) 3′-UA-5′ is required at the 3′ terminus of the minus-strand RNA for initiation of plus-strand genomic RNA synthesis; (ii) in the wild-type virus this sequence is present in a secondary structure that can be opened by the wild-type polymerase but not by the mutant polymerase; (iii) the addition of AU, AUA, or AUU to the 5′ end of the genomic RNA provides unpaired 3′-UA-5′ at the 3′ end of the minus strand that can be utilized by the mutant polymerase, and similarly, the effect of the U3A mutation is to destabilize the secondary structure, freeing 3′-terminal UA; and (iv) the N terminus of nsP4 may directly interact with the 3′ terminus of the minus-strand RNA for the initiation of the plus-strand genomic RNA synthesis. This hypothesis is discussed in light of our present results as well as of previous studies of alphavirus RNAs, including defective interfering RNAs.

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