Oligonucleotide studies: optical rotatory dispersion of normal and 2′-O-methylated diribonucleoside monophosphates

✍ Scribed by H. Singh; B. Hillier

• Publisher: Wiley (John Wiley & Sons)
• Year: 1971
• Tongue: English
• Weight: 648 KB
• Volume: 10
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360101208

✦ Synopsis

The optical i.ot:tlory dispersion (0111)) of s e v e ~a l diriboiiuc:leoside moiiophosphate+s INpN) and the correspondiiig 2'-O-methyl substituted diiiucleoside monophosphates containing 2'-O-methyl ribosyl 3'-niicleotide arid a ci'-niicleoside (NmpN) were measured a t pII 1, 7 , and 11.2, at 0.1 ionic strength iii order to examine the role of the 2'-hydroxyl group of the ribose in the conformation of the oligoribonucleotides. The optical measurements are reported from 210 to 340 mp. The PIT effect on the 0111) spectra of NpN as well as NmpN are large. No dramatic changes are seen in the shapes of the OI1D spectra of the NmpN to the corresponding N p S a t pH 7. However, a decrease in the amplitude is seen in most of the NmpN over that of the correspoiiding NpN ranging from 7 percent in the case of Ump(: to 46 percent in AmpA. The differences seen in the NpN and the correspondiiig NmpN 0111) results are best explained as a cwiseqrience of a change ill the ribosyl confornxttion on "'-O-methyl:ttiori, rather than the involvement of the 2'-hydiwyl giuup in intraniolecwlar hydrogen t)o:idiiig i n the ribo dimer. The Pr'mpN behave like NpN and not dNpdN, sriggesting that the geometry of the stlack iii NnipN and XpN depends on the oxygen a t the 2'-c:arboii arid not on what is attached to it,. * Iscued a\ AI<CI, No 4022. t T o whom all coire\pondence should be a t l d i e s d .

f. Summer sliideiit, 1969.

244.i 0 1!)71 by Johii Wiley & Soil, Iiic..