Induction, purification, and properties of 2'5' oligoadenylate synthetase.
The results presented above relate to several aspects of the 2-5A system. A simple but insensitive radiochemical assay fro 2-5A and its synthetase is described. Progress towards the molecular characterization of the synthetase suggested that it is composed of a single 56,000 dalton polypeptide chain that is synthesized in response to IF treatment. Degradation of 2-5A occurs at the same rapid rate in extracts of IF-treated and untreated chick cells. However, this breakdown can be inhibited by its end-product, 5'AMP, or by the activated synthetase which can further elongate 2-5A and thereby protect it from degradation. The direction of elongation is from the 5' to the 2' terminus. Molecules other than 2-5A can act as substrates fro 2'-adenylation by the activated synthetase. These include some dinucleoside monophosphates, ADP-ribose and NAD+, and methylene-bridged analogues of ATP. The methylene-bridged analogues of 2-5A that are synthesized in the latter case retain some of the biological activity of authentic 2-5A, indicating that cleavage of the 5'-terminal phosphate group(s) is not involved in the mechanism of nuclease activation by 2-5A.
D015088:2',5'-Oligoadenylate Synthetase; D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D004790:Enzyme Induction / Q000187:drug effects; D007372:Interferons / Q000494:pharmacology*; D009843:Oligoribonucleotides / Q000378:metabolism; D011118:Polynucleotide Ligases / Q000096:biosynthesis* / Q000302:isolation & purification; D011494:Protein Kinases / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000494:pharmacology; D013379:Substrate Specificity
D000227:Adenine Nucleotides; D009843:Oligoribonucleotides; D012330:RNA, Double-Stranded; C023505:2',5'-oligoadenylate; D007372:Interferons; D011494:Protein Kinases; D015088:2',5'-Oligoadenylate Synthetase; D011118:Polynucleotide Ligases