Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “POLYNUCLEOTIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
PubMed1998

Evidence for global mobility in the premelting of a polynucleotide from temperature-dependent Raman optical activity.

The backscattered Raman and Raman optical activity (ROA) spectra of poly(rA)-poly(rU) at 20 degrees C and 45 degrees C in buffered aqueous solution between 650 and 1750 cm(-1) are reported. Although the intensity of the majority of the Raman bands increase by varying amounts as the temperature is raised in accordance with the well-known hypochromic effect, the reverse effect is found for the ROA signals which we attribute to thermal accessibility of a greater number of distinct conformations leading to cancellation of ROA signals. The difference ROA spectrum obtained by subtracting the spectrum recorded at 45 degrees C from that recorded at 20 degrees C displays a very similar sign pattern to those at both 20 degrees C and 45 degrees C throughout the spectral region examined. This indicates that the same average structure is maintained in this temperature range and that the thermal fluctuations are correlated through the bases, the glycosidic link, the sugar ring, and the phosphate backbone of both strands. These results indicate that ROA may be a useful new probe of the dynamics of nucleic acid in solution.

Poly A-U↗
PubMed2002

Modeling of polynucleotide translocation through protein pores and nanotubes.

In an effort to understand recent experiments, we have performed Brownian dynamics simulations of polymer translocation through nanometer-scale protein pores under the influence of an external applied electric field. Multiple peaks in the translocation time distribution are observed in agreement with experiments. Under the same conditions, but replacing the protein pore with a rigid cylindrical tube of comparable size, only a single peak is observed in the translocation time distribution. These results directly show that the geometry of the protein pores is mainly responsible for multiple peaks observed in experiments. In the case of alpha-hemolysin channel, we find the vestibule, by confining many conformations of the translocating polymer, to be responsible for the second peak with longer translocation time.

Biological Transport↗