Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fragmentation”

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 397 records · Page 22Linked to original sources
PubMed1984

Carbon-13 NMR in conformational analysis of nucleic acid fragments. 2. A reparametrization of the Karplus equation for vicinal NMR coupling constants in CCOP and HCOP fragments.

13C-31P coupling constants of 10 oligoribonucleoside phosphates, measured at a number of temperatures, are presented. The combination of these data with 1H-31P couplings of the same compounds leads to the derivation of two new and mutually consistent sets of Karplus parameters: J(CCOP) = 6.9cos2 phi--3.4cos phi + 0.7 J(HCOP) = 15.3cos2 phi--6.1cos phi + 1.6 At the same time new values for the base sequence dependent magnitude of the trans conformer of the backbone angle epsilon (C4'-C3'-O3'-P) are calculated. The present results show that the magnitude of epsilon(t) in right-handed ribo helices is confined to the range 214 degrees-226 degrees (average 219 degrees), which is in much better agreement with single crystal X-ray studies (average 218 degrees) than were previous deductions from NMR spectroscopic results (average 208 degrees).

Carbon Isotopes↗