title: Mechanism of spermine stimulation of rat-liver isoleucyl-tRNA formation.
abstract: The mechanism of spermine stimulation of rat-liver isoleucyl-tRNA formation has been studied by Cleland's method [Biochim. Biophys. Acta, 67, 104--137 & 173--197 (1963)]. It was demonstrated that isoleucyl-tRNA formation proceeded through a ping-pong mechanism in the presence of spermine and magnesium. From a study of the effect of spermine on both the formation of isoleucyl-AMP . enzyme complex and on the subsequent formation of isoleucyl-tRNA from the isoleucyl-AMP . enzyme complex, evidence is presented that the stimulatory effect of spermine functions mainly through the spermine preventing the tRNA inhibition of isoleucyl-AMP . enzyme complex formation.
mesh_terms: D000255:Adenosine Triphosphate; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000818:Animals; D004789:Enzyme Activation; D007532:Isoleucine; D007533:Isoleucine-tRNA Ligase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D012343:RNA, Transfer; D051381:Rats; D013096:Spermine / Q000494:pharmacology*
chemical_list: D007532:Isoleucine; D013096:Spermine; D000255:Adenosine Triphosphate; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases; D007533:Isoleucine-tRNA Ligase; D008274:Magnesium; D011188:Potassium