title: Synthesis and biological activities of beta-alanyltyrosine derivative of 2',5'-oligoadenylate, and its use in radiobinding assay for 2',5-oligoadenylate.
abstract: beta-Alanyltyrosine derivative of 2',5'-tetraadenylate 5'-triphosphate, pppA2'p5'A2'-p5'A2'p5'A-beta-Ala-Tyr was prepared by coupling of periodate-oxidized pppA2'p5'-A2'p5'A2'p5'A with beta-alanyltyrosine methyl ester, followed by reduction with sodium cyanoborohydride. Its stability to 2',5'-phosphodiesterase and phosphatase was investigated in mouse L cell extract. The 5'-triphosphate of the compound was cleaved gradually to form the 5'-dephosphorylated derivative, A2'p5'A2'p5'A2'p5'A-beta-Ala-Tyr, followed by slow degradation of the 2',5'-phosphodiester bond. On the other hand, pppA2'p5'A2'p5'A2'p5'A was hydrolyzed very quickly under the same conditions. The tetramer derivative bound tightly to the 2',5'-oligoadenylate-dependent endoribonuclease in rabbit reticulocyte lysate or mouse L cell extract and inhibited protein synthesis of mouse L cells more effectively than the unmodified 2',5'-tetraadenylate 5'-triphosphate. The corresponding trimer derivative had slightly weaker activities than the unmodified trimer for binding to the endoribonuclease and for inhibition of protein synthesis. The compound, pppA2'p5'A2'p5'-A2'p5'A-beta-Ala-Tyr, was iodinated easily at the tyrosine residue with 125I, giving a high-specific-radioactivity derivative which was used as a radio-labeled probe in a radiobinding assay for 2',5'-oligoadenylate.
mesh_terms: D000227:Adenine Nucleotides / Q000032:analysis*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D007553:Isotope Labeling; D007739:L Cells; D051379:Mice; D009843:Oligoribonucleotides / Q000032:analysis* / Q000138:chemical synthesis* / Q000378:metabolism; D014176:Protein Biosynthesis; D011869:Radioligand Assay
chemical_list: D000227:Adenine Nucleotides; D009843:Oligoribonucleotides; C047922:beta-alanyltyrosine-2',5'-oligoadenylate 5'-triphosphate; C023505:2',5'-oligoadenylate