title: pppA2'p5'A2'p5'A: an inhibitor of protein synthesis synthesized with an enzyme fraction from interferon-treated cells.
abstract: A low molecular weight inhibitor of cell-free protein synthesis effective at subnanomolar concentrations is formed on incubation of cytoplasmic extracts from interferon-treated cells with double-stranded RNA and ATP. It can be conveniently synthesized by incubating a poly(I).poly(C)-Sepharose-bound enzyme fraction from such cells with [3H]- or [alpha- or gamma-32P]ATP. The radioactive inhibitor has been characterized by its behavior on DEAE-Sephadex in the presence of urea and on the basis of the products obtained on enzymic, alkaline, and sequential degradation by periodate oxidation and beta elimination. Its structure appears to be pppA2'p5'A2'p5'A. We have found no evidence for any modification or abnormality other than the 2'-5' linkage. On occasion the inhibitor preparations have included what seems to be the corresponding dimer (pppA2'p5'A), tetramer [ppp(A2'p)3A], pentamer [ppp(A2'p)4A], and higher oligomers in decreasing amounts. The trimer, tetramer, and pentamer are similar in activity, but the dimer is less potent if active at all.
mesh_terms: D003864:Depression, Chemical; D007372:Interferons / Q000494:pharmacology*; D007739:L Cells; D008970:Molecular Weight; D009841:Oligonucleotides / Q000096:biosynthesis*; D009843:Oligoribonucleotides / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D014176:Protein Biosynthesis / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D009841:Oligonucleotides; D009843:Oligoribonucleotides; D007372:Interferons
references.citation: Proc Natl Acad Sci U S A. 1976 Sep;73(9):3112-6
references.pmid: 184460
references.citation: Nature. 1977 Aug 11;268(5620):540-2
references.pmid: 196217
references.citation: Nature. 1976 Dec 2;264(5585):477-80
references.pmid: 1004583
references.citation: FEBS Lett. 1976 Sep 15;68(1):119-24
references.pmid: 964373
references.citation: Cell. 1976 Sep;9(1):121-30
references.pmid: 975236
references.citation: Proc Natl Acad Sci U S A. 1977 Aug;74(8):3326-9
references.pmid: 198782
references.citation: Proc Natl Acad Sci U S A. 1977 Apr;74(4):1445-9
references.pmid: 193100
references.citation: Nature. 1976 Sep 9;263(5573):163-5
references.pmid: 184395
references.citation: Cell. 1977 May;11(1):187-200
references.pmid: 559547
references.citation: Anal Biochem. 1977 May 1;79(1-2):16-22
references.pmid: 869174
references.citation: Proc Natl Acad Sci U S A. 1976 Sep;73(9):3107-11
references.pmid: 1067606
references.citation: Nature. 1976 Nov 25;264(5584):370-3
references.pmid: 1004563
references.citation: J Chromatogr. 1973 May 16;79:139-46
references.pmid: 4350764
references.citation: J Chromatogr. 1969 Mar 11;40(1):103-9
references.pmid: 5777609