[Adenosine- and ethenoadenosine-5'-trimetaphosphates: the effect of covalent bond formation on the state of the affinity label in the complex with phenylalanyl-tRNA-synthetase].
epsilon ATP is a substrate of phenylalanyl-tRNA synthetase and epsilon Ado is a competitive inhibitor of ATP in the reaction of tRNA aminoacylation (Ki = 1.6 mM). The association of phenylalanyl-tRNA synthetase with ATP or Ado results in synergistic binding of phenylalaninol and phenylalanine, respectively. However neither epsilon ATP nor epsilon Ado exhibit synergism. Adenosine- and ethenoadenosine-5'-trimethaphosphates are shown to be similar affinity reagents of phenylalanyl-tRNA synthetase. ATP being covalently bound to the enzyme shows essentially lower synergistic effect in comparison with free ATP. epsilon ATP-label is practically insensitive to the ligands namely ATP, Phe, phenylalaninol and is highly accessible for I- ions. The scheme of behaviour of affinity labels is assumed to be as follows: a) the formation of specific reagent-enzyme complex, b) the covalent attachment of the reagent to the enzyme, c) the covalent binding induced disruption of the specific complex formed before.
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism*; D000345:Affinity Labels / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D004926:Escherichia coli / Q000201:enzymology; D004985:Ethenoadenosine Triphosphate / Q000378:metabolism*; D007700:Kinetics; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D013379:Substrate Specificity
D000345:Affinity Labels; D004985:Ethenoadenosine Triphosphate; D012346:RNA, Transfer, Amino Acyl; D000255:Adenosine Triphosphate
Adenozin- i étenoadenozin-5'-trimetafosfaty: vliianie obrazovaniia kovalentnoĭ sviazi na sostoianie affinnoĭ metki v komplekse s fenilalanil-tRNK-sintetazoĭ.