SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Chattopadhyaya J) "

Sökning: WFRF:(Chattopadhyaya J)

  • Resultat 1-50 av 114
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  •  
3.
  •  
4.
  •  
5.
  •  
6.
  •  
7.
  • Glemarec, C, et al. (författare)
  • The NMR structure of 31-mer RNA domain of E. coli RNase P RNA using its non-uniformly deuterium labelled counterpart (the "NMR-window" concept)
  • 1996
  • Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 24:11, s. 2022-2035
  • Tidskriftsartikel (refereegranskat)abstract
    • The NMR structure of a 31mer RNA constituting a functionally important domain of the catalytic RNase P RNA from Escherichia coli is reported. Severe spectral overlaps of the proton resonances in the natural 31mer RNA (1) were successfully tackled by unique spectral simplifications found in the partially-deuterated 31 mer RNA analogue (2) incorporating deuterated cytidines [C5 (>95 atom % 2H), C2' (>97 atom % 2H), C3' (>97 atom % 2H), C4' (>65 atom % 2H) and C5' (>97 atom % 2H)] [for the 'NMR-window' concept see: Földesi,A. et al. (1992) Tetrahedron, 48, 9033; Foldesi,A. et al. (1993) J. Biochem. Biophys. Methods, 26, 1; Yamakage,S.-I. et al. (1993) Nucleic Acids Res., 21, 5005; Agback,P. et al. (1994) Nucleic Acids Res., 22, 1404; Földesi,A. et al. (1995) Tetrahedron, 51, 10065; Földesi,A. et al. (1996) Nucleic Acids Res., 24, 1187-1194]. 175 resonances have been assigned out of total of 235 non-exchangeable proton resonances in (1) in an unprecedented manner in the absence of 13C and 15N labelling. 41 out of 175 assigned resonances could be accomplished with the help of the deuterated analogue (2). The two stems in 31mer RNA adopt an A-type RNA conformation and the base-stacking continues from stem I into the beginning of the loop I. Long distance cross-strand NOEs showed a structured conformation at the junction between stem I and loop I. The loop I-stem II junction is less ordered and shows structural perturbation at and around the G11 -C22 base pair.
  •  
8.
  •  
9.
  •  
10.
  •  
11.
  • Milecki, J, et al. (författare)
  • Synthesis of multiply labelled ribonucleosides for sequence-specific labelling of oligo-RNA
  • 2001
  • Ingår i: JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS. - : JOHN WILEY & SONS LTD. - 0362-4803. ; 44:11, s. 763-783
  • Tidskriftsartikel (refereegranskat)abstract
    • The synthesis of ribonucleotide blocks multiply labelled with H-2, C-13 and N-15 for solid support synthesis of sequence specifically labelled RNA is described. Labels were introduced in the ribose ring ( C-13), C5 position of pyrimidine nucleobases (H-2)
  •  
12.
  •  
13.
  • PAPCHIKHIN, A, et al. (författare)
  • THE DIASTEREOSPECIFIC SYNTHESIS OF NEW 2',3'-CIS-ALPHA-FUSED CARBOCYCLIC NUCLEOSIDES
  • 1995
  • Ingår i: TETRAHEDRON. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0040-4020. ; 51:1, s. 329-342
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The first diastereospecific synthesis of [3.3.0]- and [3.4.0]-alpha-cis-fused-carbocyclic nucleosides 10, 12 and 20, starting directly from 2'-O-(TBDMS) or 3'-O-(TBDMS) derivatives of 5'-O-MMTr-2',3'-seco-ribo-thymidines, 1 and 13 (ref. 4), have been repo
  •  
14.
  •  
15.
  •  
16.
  •  
17.
  • PLAVEC, J, et al. (författare)
  • REPARAMETRIZATION OF KARPLUS EQUATION RELATING (3)J(C-C-O-P) TO TORSION ANGLE
  • 1995
  • Ingår i: TETRAHEDRON LETTERS. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0040-4039. ; 36:11, s. 1949-1952
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • A new three-parameter Karplus equation (3)J(C-C-O-P) = 9.1 cos(2) Phi - 1.9 cos Phi + 0.8 is based on the 17 (3)J(CP) coupling constants and the corresponding X-ray derived torsion angles giving an r.m.s. of 0.3 Hz and Delta J < 0.5 Hz between J(exp) and
  •  
18.
  •  
19.
  •  
20.
  •  
21.
  •  
22.
  •  
23.
  • Acharya, Parag, et al. (författare)
  • Cross-Modulation of the pKa of Nucleobases in a Single-Stranded Hexameric-RNA Due to Tandem Electrostatic Nearest-Neighbor Interactions
  • 2003
  • Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 125:33, s. 9948-9961
  • Tidskriftsartikel (refereegranskat)abstract
    • The pH titration studies (pH 6.7-12.1) in a series of dimeric, trimeric, tetrameric, pentameric, and hexameric oligo-RNA molecules [GpA (2a), GpC (3a), GpApC (5), GpA(1)pA(2)pC (6), GpA(1)pA(2)pA(3)pC (7), GpA(1)pA(2)pA(3)pA(4)pC (8)] have shown that the pK(a) of N(1)-H of 9-guaninyl could be measured not only from its own deltaH8G, but also from the aromatic marker protons of other constituent nucleobases. The relative chemical shift differences [Deltadelta((N)(-)(D))] between the protons in various nucleotide residues in the oligo-RNAs at the neutral (N) and deprotonated (D) states of the guanine moiety show that the generation of the 5'-(9-guanylate ion) in oligo-RNAs 2-8 reduces the stability of the stacked helical RNA conformation owing to the destabilizing anion(G(-))-pi/dipole(Im(delta)(-)) interaction. This destabilizing effect in the deprotonated RNA is, however, opposed by the electrostatically attractive atom-pisigma (major) as well as the anion(G(-))-pi/dipole(Py(delta)(+)) (minor) interactions. Our studies have demonstrated that the electrostatically repulsive anion(G(-))-pi/dipole(Im(delta)(-)) interaction propagates from the first to the third nucleobase quite strongly in the oligo-RNAs 6-8, causing destacking of the helix, and then its effect is gradually reduced, although it is clearly NMR detectable along the RNA chain. Thus, such specific generation of a charge at a single nucleobase moiety allows us to explore the relative strength of stacking within a single-stranded helix. The pK(a) of 5'-Gp residue from its own deltaH8G in the hexameric RNA 8 is found to be 9.76 +/- 0.01; it, however, varies from 9.65 +/- 0.01 to 10.5 +/- 0.07 along the RNA chain as measured from the other marker protons (H2, H8, H5, and H6) of 9-adeninyl and 1-cytosinyl residues. This nucleobase-dependent modulation of pK(a)s (DeltapK(a) +/- 0.9) of 9-guaninyl obtained from other nucleobases in the hexameric RNA 8 represents a difference of ca. 5.1 kJ mol(-)(1), which has been attributed to the variable strength of electrostatic interactions between the electron densities of the involved atoms in the offset stacked nucleobases as well as with that of the phosphates. The chemical implication of this variable pK(a) for guanin-9-yl deprotonation as obtained from all other marker protons of each nucleotide residue within a ssRNA molecule is that it enables us to experimentally understand the variation of the electronic microenvironment around each constituent nucleobase along the RNA chain in a stepwise manner with very high accuracy without having to make any assumption. This means that the pseudoaromaticity of neighboring 9-adeninyl and next-neighbor nucleobases within a polyanionic sugar-phosphate backbone of a ssRNA can vary from one case to another due to cross-modulation of an electronically coupled pi system by a neighboring nucleobase. This modulation may depend on the sequence context, spatial proximity of the negatively charged phosphates, as well as whether the offset stacking is ON or OFF. The net outcome of this electrostatic interaction between the neighbors is creation of new sequence-dependent hybrid nucleobases in an oligo- or polynucleotide whose properties are unlike the monomeric counterpart, which may have considerable biological implications.
  •  
24.
  •  
25.
  •  
26.
  •  
27.
  •  
28.
  •  
29.
  •  
30.
  •  
31.
  •  
32.
  •  
33.
  • Amirkhanov, NV, et al. (författare)
  • The recognition and cleavage of RNA in the antisense oligo-RNA hybrid duplexes by RNase H
  • 2001
  • Ingår i: TETRAHEDRON LETTERS. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0040-4039. ; 42:3, s. 489-491
  • Tidskriftsartikel (refereegranskat)abstract
    • The different extent of the target RNA cleavage at t(99.9%) by RNase H in the AON-RNA duplexes, at the RNA saturation condition by antisense oligo, is due to different recognition and catalytic properties of RNase H toward the hybrids owing to different s
  •  
34.
  •  
35.
  •  
36.
  •  
37.
  • BURKHART, BM, et al. (författare)
  • 2',3'-DIDEOXY-3'-C,2'-N-[(3R,5R)-5-ETHOXYCARBONYL-2-METHYL-1,2-ISOXAZOLIDINE]-RIBOTHYMIDINE
  • 1995
  • Ingår i: ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS. - 0108-2701. ; 51, s. 1462-1464
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The title compound, C15H21N3O7, is a thymidine derivative with a tetrahydroisoxazole (THI) ring fused to the sugar ring at the 2'- and 3'-C atoms, The thymine base is in an anti conformation [chi = -122.5 (3)degrees] while the ribose moiety has a C2'-exo,
  •  
38.
  •  
39.
  •  
40.
  •  
41.
  •  
42.
  •  
43.
  •  
44.
  •  
45.
  •  
46.
  •  
47.
  •  
48.
  •  
49.
  •  
50.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 114

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy