title: The thermodynamics of 3'-terminal pyrene and guanosine for the design of isoenergetic 2'-O-methyl-RNA-LNA chimeric oligonucleotide probes of RNA structure.
abstract: To facilitate design of short isoenergetic hybridization probes for RNA, we report the influence of adding 5'- or 3'-terminal 2'-O-methylguanosine (GM), LNA-guanosine (GL), or 3'-terminal pyrene pseudo-nucleotide (PPN) on the thermodynamic stability of 2'-O-methyl-RNA/RNA (2'-O-Me-RNA/RNA) duplexes with sequences 5'CMGMGMCMAM/3'AAXGCCGUXAA, where X is A, C, G, or U. A 3'-terminal GM or GL added to the 2'-O-Me-RNA strand to form a G-A, G-G or G-U mismatch enhances thermodynamic stability (DeltaDeltaG degrees 37) of the 2'-O-Me-RNA/RNA duplexes on average by 0.7 and 1.5 kcal/mol, respectively. A 3'-terminal GM or GL in a GM-C or GL-C pair stabilizes the 2'-O-Me-RNA/RNA duplex by 2.6 and 3.4 kcal/mol, respectively. A 5'-terminal GM or GL in a G-A or G-G mismatch provided less stabilization in comparison with a 3'-terminal G-A or G-G mismatch, but more stabilization in a G-C or G-U pair. In contrast to guanosine derivatives, pyrene residue (P) as PPN at the 3'-terminal position enhances thermodynamic stability of the 2'-O-Me-RNA/RNA duplexes on average by 2.3 +/- 0.1 kcal/mol, relatively independent of the type of ribonucleotide placed in the opposite strand. The thermodynamic data can be applied to design 2'-O-Me-RNA/RNA duplexes with enhanced thermodynamic stability that is also sequence independent. This is useful for design of hybridization probes to interrogate RNA structure and/or expression by microarray and other methods.
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, 60-714 Poznan, Noskowskiego 12/14, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Pasternak
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Kierzek
authors.forename: Karol
authors.initials: K
authors.lastname: Pasternak
authors.forename: Agata
authors.initials: A
authors.lastname: Fratczak
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Turner
authors.forename: Ryszard
authors.initials: R
authors.lastname: Kierzek
mesh_terms: D004355:Drug Stability; D006151:Guanosine / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D015345:Oligonucleotide Probes / Q000138:chemical synthesis*; D009841:Oligonucleotides / Q000138:chemical synthesis*; D011721:Pyrenes / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D015345:Oligonucleotide Probes; D009841:Oligonucleotides; D011721:Pyrenes; C477371:locked nucleic acid; D006151:Guanosine; D012313:RNA; C030984:pyrene