Effects on ribosomes of the substitution of spermidine or divalent cations for magnesium ions.
The inactivation of rat liver ribosomes (polysomes) resulting from the replacement of bound magnesium by spermidine has been studied using a dialysis method. Inactivation of the ribosomes (polysomes) occurred when more than 40% of the Mg2+ originally bound to ribosomes in the presence of 2 mM Mg2+ was replaced by spermidine. The polypeptide-synthesizing activity of polysomes was retained partially when Mg2+ was replaced by Mn2+ by dialysis. E. coli 30S ribosomal subunits were more resistant to inactivation due to the replacement of Mg2+ by spermidine than the 50S subunits.
D000818:Animals; D002413:Cations, Divalent; D003956:Dialysis; D004926:Escherichia coli / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism; D010452:Peptide Biosynthesis; D011132:Polyribosomes / Q000378:metabolism; D051381:Rats; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*; D013095:Spermidine / Q000494:pharmacology*
D002413:Cations, Divalent; D008345:Manganese; D008274:Magnesium; D013095:Spermidine