TY - JOUR
T1 - Effect of adenosylhomocysteine and other analog thioethers on a prokaryotic tRNA (guanine-7)-methyltransferase
AU - Paolella, Giovanni
AU - Ciliberto, Gennaro
AU - Traboni, Cinzia
AU - Cimino, Filiberto
AU - Salvatore, Francesco
PY - 1982
Y1 - 1982
N2 - S-Adenosylhomocysteine (SAH), a potent inhibitor of methyltransferases, and several thioethers structurally related to SAH, have been tested as potential inhibitors of tRNA (guanine-7)-methyltransferase from Salmonella typhimurium. The tested compounds are l-, d-, dl-S-adenosylhomocysteine, S-adenosylcysteine, methylthioadenosine, butylthioadenosine, thioethanoladenosine, isobutylthioadenosine, S-inosylhomocysteine, and methylthioinosine. Among them the highest inhibitory activity has been shown by SAH (Ki = 8 μM), whereas butylthioadenosine, isobutylthioadenosine, and thioethanoladenosine are almost inactive as inhibitors. The other compounds inhibit the enzyme with Ki values ranging between 400 and 800 μm. From these data it is possible to evaluate the importance of the -NH2 and -COOH groups of the substrate in the binding to the enzyme molecule, as well as other features such as the chirality at the α-carbon atom and the length of the hydrocarbon chain connecting the -NH2 and -COOH groups to the aromatic ring of adenosine. The aminic group of the adenosine is also critical, because S-inosylhornocysteine and methylthioinosine are poorer inhibitors in comparison with SAH and methylthioadenosine.
AB - S-Adenosylhomocysteine (SAH), a potent inhibitor of methyltransferases, and several thioethers structurally related to SAH, have been tested as potential inhibitors of tRNA (guanine-7)-methyltransferase from Salmonella typhimurium. The tested compounds are l-, d-, dl-S-adenosylhomocysteine, S-adenosylcysteine, methylthioadenosine, butylthioadenosine, thioethanoladenosine, isobutylthioadenosine, S-inosylhomocysteine, and methylthioinosine. Among them the highest inhibitory activity has been shown by SAH (Ki = 8 μM), whereas butylthioadenosine, isobutylthioadenosine, and thioethanoladenosine are almost inactive as inhibitors. The other compounds inhibit the enzyme with Ki values ranging between 400 and 800 μm. From these data it is possible to evaluate the importance of the -NH2 and -COOH groups of the substrate in the binding to the enzyme molecule, as well as other features such as the chirality at the α-carbon atom and the length of the hydrocarbon chain connecting the -NH2 and -COOH groups to the aromatic ring of adenosine. The aminic group of the adenosine is also critical, because S-inosylhornocysteine and methylthioinosine are poorer inhibitors in comparison with SAH and methylthioadenosine.
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U2 - 10.1016/0003-9861(82)90143-6
DO - 10.1016/0003-9861(82)90143-6
M3 - Article
C2 - 6758702
AN - SCOPUS:0020403192
VL - 219
SP - 149
EP - 154
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -