排序方式: 共有57条查询结果,搜索用时 15 毫秒
1.
2.
When three-dimensional NMR spectra are presented as two stereoscopic images, they create a convincing three-dimensional impression for the viewer. In an extension of this principle, we record plane projections of a three-dimensional spectrum at different angles, and use this limited information to reconstruct the entire spectrum. Projections onto different skew planes are derived by Fourier transformation of signals acquired while the two evolution parameters are incremented simultaneously at different rates. By limiting the amount of data gathering, this offers an appreciable economy of instrument time. Normally two to six different projections suffice, depending on the complexity of the spectra. There is an order-of-magnitude speed advantage over the conventional methodology, where both evolution dimensions must be explored independently. Results are presented for reconstructed HNCA and HN(CO)CA spectra of ubiquitin and the HNCO spectrum of a 187-residue protein HasA. 相似文献
3.
Paul Tanui Martin Kullberg Ni Song Yashodhan Chivate Eriks Rozners 《Tetrahedron》2010,66(27-28):4961-4964
Amides as neutral and hydrophobic internucleoside linkages in RNA are highly interesting modifications for RNA interference. However, testing amides in siRNAs is hampered by the shortage of efficient methods to synthesize the monomeric building blocks, the nucleoside amino acid equivalents. This paper reports an efficient synthesis of protected ribonucleoside 5′-amino 3′-carboxylic acids from d-xylose in 14 steps 7% overall yield. The key features that ensure efficiency and ease of operations are chemoselective reduction of the ester and minimization of protecting group manipulation. 相似文献
4.
Muthiah Manoharan Akin Akinc Rajendra K. Pandey June Qin Philipp Hadwiger Matthias John Kathy Mills Klaus Charisse Martin A. Maier Lubomir Nechev Emily M. Greene Pradeep S. Pallan Eriks Rozners Kallanthottathil G. Rajeev Martin Egli 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2011,123(10):2332-2336
5.
6.
Peptide nucleic acids containing 2-pyrimidinone (P) and 3-oxo-2,3-dihydropyridazine (E) heterocycles recognized C-G and U-A inversions in a polypurine tract of double helical RNA with high affinity and sequence selectivity at pH 6.25. E-modified PNA bound strongly to bacterial A-site RNA, while no binding was observed to the human A-site RNA. 相似文献
7.
Cover Picture: Nucleobase‐Modified PNA Suppresses Translation by Forming a Triple Helix with a Hairpin Structure in mRNA In Vitro and in Cells (Angew. Chem. Int. Ed. 3/2016)
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
8.
Two-dimensional nitrogen-carbon NMR correlation spectra have been derived by a new reconstruction technique based on standard two-dimensional HMQC and HMBC spectra, and operating with natural 15N and 13C isotopic abundances. Compared with conventional three-dimensional spectroscopy in which 15N and 13C spins must be present in the same molecule, the reconstruction method offers two orders of magnitude improvement in sensitivity. Vitamin B-12 serves as an illustrative example. 相似文献
9.
Nikita Brodyagin Aubrey L. Maryniak Ilze Kumpina John M. Talbott Dr. Martins Katkevics Prof. Dr. Eriks Rozners Prof. Dr. James A. MacKay 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(13):4332-4335
Peptide nucleic acids (PNA) with extended isoorotamide containing nucleobases ( I o ) were designed for binding A–U base pairs in double-stranded RNA. Isothermal titration calorimetry and UV thermal melting experiments revealed improved affinity for A–U using the Io scaffold in PNA. PNAs having four sequential Io extended nucleobases maintained high binding affinity. 相似文献
10.
The acquisition of multidimensional NMR spectra can be speeded up by a large factor by a projection-reconstruction method related to a technique used in X-ray scanners. The information from a small number of plane projections is used to recreate the full multidimensional spectrum in the familiar format. Projections at any desired angle of incidence are obtained by Fourier transformation of time-domain signals acquired when two or more evolution intervals are incremented simultaneously at different rates. The new technique relies on an established Fourier transform theorem that relates time-domain sections to frequency-domain projections. Recent developments in NMR instrumentation, such as increased resolution and sensitivity, make fast methods for data gathering much more practical for protein and RNA research. Hypercomplex Fourier transformation generates projections in symmetrically related pairs that provide two independent "views" of the spectrum. A new reconstruction algorithm is proposed, based on the inverse Radon transform. Examples are presented of three- and four-dimensional NMR spectra of nuclease A inhibitor reconstructed by this technique with significant savings in measurement time. 相似文献