PubMed Health⌕ Search

Biomedical subjects

E Biała

Publications and source records attributed to E Biała.

6 recordsLinked to original sources
PubMed2001

Elements of thermodynamics in RNA evolution.

The paper presents some aspects correlating thermal stability of RNA folding and the occurrence of structural motifs in natural ribonucleic acids. Particularly, the thermodynamic stability of 2'-5' and 3'-5' linked RNA and the contribution of unpaired terminal nucleotides (dangling ends) in secondary (2D) and tertiary (3D) structures of RNA are discussed. Both examples suggest that during evolution nature selected sequences and structures of RNA which are the most thermally stable and efficient for their biological function.

Base Sequence↗
PubMed1993

Z-RNA. The synthesis of 2'-O-[13C]methyl- and 5-methyl-analogs of ribo-CGCGCG.

Chemical synthesis of 2'-O-[13C]methyl-rCGCGCG and 5-methyl-rCGCGCG using support-aided phosphoramidite method is presented. 2'-O-Methyl guanosine derivative was separated from its 3'-O-methyl counterpart using transient 5',3'-O-silylation with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (Markiewicz reagent). The hexamers were obtained in a purity suitable for NMR studies.

Base Sequence↗
PubMed1985

New, ionic side-products in oligonucleotide synthesis: formation and reactivity of fluorescent N-/purin-6-yl/pyridinium salts.

Fluorescent N-/purin-6-yl/pyridinium salts are formed in pyridine assisted phosphorylations and arenesulphonations of the hypoxanthine lactam system under various conditions including those used in oligonucleotide synthesis. The N1-methyl-N3-/purin-6-yl/imidazolium salt is generated in phosphorylation with TPSCl/1-methylimidazole as a coupling system. Both salts are representatives of a new family of ionic side-products in oligonucleotide synthesis involving hypoxanthine residues. Their isolation procedure has been developed. High reactivity of N-/purin-6-yl/pyridinium salts towards some reagents used in oligonucleotide chemistry, e.g. pyridinium mediated conversion of hypoxanthine into 6-aminopurine, can result in point mutations in synthesized oligomer.

Fluorescent Dyes↗
PubMed1980

Further studies on oligoribonucleotide synthesis.

Recent results concerning the synthesis of oligoribonucleotides via the phosphotriester method, such as functionalization of ribonucleosides, new phosphorylating agents, 5'-O-sulfonylation and chromatography on Sephadex LH-20 for monitoring the removal of internucleotide phosphotriester groups, are presented. To show that efficiency of a new approach to the synthesis of oligoribonucleotides the pentamer /Up/4U was obtained.

Esters↗
PubMed1978

The chemical synthesis of the anticodon loop of an eukaryotic initiator tRNA containing the hypermodified nucleoside N6-/N-threonylcarbonyl/-adenosine/t6A/1.

In this work, the first example of chemical synthesis of oligoribonucleotide containing the hypermodified nucleoside N6-/N-threonylcarbonyl/-adenosine /t6A/ is presented. Synthesis of the heptamer C-C-C-A-U-t6A-A IX, the sequence of which is related to the anticodon loop of the initiator tRNA from yellow lupine, was achieved by: /i/ phosphotriester block synthesis of suitably protected heptamer VI containing an adenosine unit with a free exo-NH2 group, /ii/ highly effective "one-flask" procedure for the transformation of the free exo-NH2 group of adenosine unit of heptamer VI into a N,N'-disubstituted urea system of t6A of heptamer VII /hypermodification/, and /iii/ final deprotection of VIII /32% total yield/ with the use of a new approach for simultaneous hydrogenolysis /PdO-hydrogen-pyridine/ of the p-nitrobenzyl group and 2,2,2-trichloroethyl groups from carboxyl function of t6A and internucleotide phosphates respectively.

Adenosine↗