title: Studies on transfer ribonucleic acids and related compounds. XL. Synthesis of an eicosaribonucleotide corresponding to residues 35-54 of tRNAfMet from E. coli.
abstract: An E. coli tRNAfMet fragment [C-A-U-A-A-C-C-C-G-A-A-G-G-U-C-G-U-C-G-G (bases 35-f54)] containing the anticodon triplet has been synthesized by the phosphotriester method involving protected oligonucleotide blocks. Di- or tri-nucleotide blocks were prepared by condensation of 2'-O-(o-nitrobenzyl) nucleotide derivatives and used for the synthesis of pentanucleotide blocks. The 5'-hydroxy, heterocyclic amino and internucleotide linkage were protected with monomethoxytrityl, acyl and p-chlorophenyl groups, respectively. The 3'-phosphates of the pentanucleotides, except for the GUCGG block where 2'-O-benzoyl 3'-O-(o-nitrobenzyl) N-isobutyrylguanosine was used, were protected with p-chlorophenyl and anilido groups. The anilido groups were removed by treatment with isoamyl nitrite and the 3'-phosphodiesters of resulting pentamers were activated with mesitylenesulfonyl nitrotriazolide to give protected decanucleotides in yields of 61-89%. The two decanucleotides were condensed similarly to yield the protected eicosanucleotide in a yield of 59%. The product was deblocked and purified by ion-exchange chromatography on DEAE-Sephadex A-25 and characterized by enzymatic hydrolysis after labelling the 5'-end by phosphorylation using polynucleotide kinase and [gamma-32P]ATP.
mesh_terms: D000926:Anticodon; D001483:Base Sequence; D015226:Dinucleoside Phosphates; D004926:Escherichia coli / Q000032:analysis*; D007202:Indicators and Reagents; D009690:Nucleic Acid Conformation; D009705:Nucleosides / Q000138:chemical synthesis; D009841:Oligonucleotides / Q000138:chemical synthesis*; D009843:Oligoribonucleotides / Q000138:chemical synthesis*; D012343:RNA, Transfer / Q000032:analysis*; D012346:RNA, Transfer, Amino Acyl / Q000032:analysis*; D012358:RNA, Transfer, Met
chemical_list: D000926:Anticodon; D015226:Dinucleoside Phosphates; D007202:Indicators and Reagents; D009705:Nucleosides; D009841:Oligonucleotides; D009843:Oligoribonucleotides; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; C024988:tRNA, formylmethionine-; D012343:RNA, Transfer