title: Dissection of the roles of adenine ring nitrogen (N-1) and exocyclic amino (N-6) moieties in the interaction of 2-5A with RNase L.
abstract: To elucidate further the roles played by the adenine bases in the interaction of RNase L (EC 3.1.2.6) with the 2',5'-oligoadenylate 2-5A, p5'A2'(p5'A2')np5' A, a series of sequence-specific 1-deazaadenosine (c1A)-substituted analogues were synthesized and evaluated for their ability to bind to and activate human RNase L in comparison to earlier reported inosine-substituted congeners of 2-5A. Substitution of only the 5'-terminal adenosine of p5'A2'p5'A2 p5 A with c1A afforded an analogue with strongly diminished RNase L binding and activation ability, while replacement of the second or middle adenosine of p5 A2' p5'A2'p5' A had only a modest effect. In distinct contrast to p5'A2'p5'A2'p5'I, the c1A analogue with the third or 2'-terminal adenosine replacement approached parent p5' A2'p5'A2'p5' A in RNase L activation ability. These results permitted a further dissection of the role of various nucleotidic functional groups in the interaction of 2-5A with RNase L: specifically, that the 5'-terminal adenosine purine N-1 moiety is key for binding to RNase L, while the 2'-terminal adenosine N-6 exocyclic amino group is critical for RNase L activation.
authors.affiliation: Section on Biomedical Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0805, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Player
authors.forename: E N
authors.initials: EN
authors.lastname: Kalinichenko
authors.forename: T L
authors.initials: TL
authors.lastname: Podkopaeva
authors.forename: I A
authors.initials: IA
authors.lastname: Mikhailopulo
authors.forename: F
authors.initials: F
authors.lastname: Seela
authors.forename: P F
authors.initials: PF
authors.lastname: Torrence
mesh_terms: D000227:Adenine Nucleotides / Q000494:pharmacology*; D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D015394:Molecular Structure; D009843:Oligoribonucleotides / Q000378:metabolism / Q000494:pharmacology*; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D014372:Tubercidin / Q000737:chemistry
chemical_list: D000227:Adenine Nucleotides; D009843:Oligoribonucleotides; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C048086:1-deazaadenosine; C023505:2',5'-oligoadenylate; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease; D000241:Adenosine; D014372:Tubercidin