Stayton M M, Fromm H J
J Biol Chem. 1979 Apr 25;254(8):2579-81.
The mechanism of ppGpp inhibition of adenylosuccinate synthetase (EC 6.3.4.4) was examined. Initial rate kinetic studies demonstrate the ppGpp inhibition is competitive with respect to GTP and noncompetitive with respect to L-aspartate and IMP. This is in contrast to an earlier report (Gallant, J., Irr, J., and Cashel, M. (1971) J. Biol. Chem. 246, 5812-5816), which suggested that ppGpp did not bind at the GTP site. Possible reasons for the discrepancy are discussed. The potency of the ppGpp inhibition is confirmed.
研究了ppGpp对腺苷琥珀酸合成酶（EC 6.3.4.4）的抑制机制。初始速率动力学研究表明，ppGpp的抑制作用在GTP方面具有竞争性，而在L-天冬氨酸和IMP方面是非竞争性的。这与早期的一份报告（加兰特，J.，伊尔，J.，和卡舍尔，M.（1971年）《生物化学杂志》246，5812 - 5816）形成对比，该报告表明ppGpp不在GTP位点结合。讨论了差异存在的可能原因。ppGpp抑制作用的效力得到了证实。
