TEMPLATE-DEPENDENT POLYPEPTIDE-SYNTHESIS IN A FACTOR-FREE AND ENERGY-FREE TRANSLATION SYSTEM PROMOTED BY PYRIDINE

We demonstrate here that a high concentration (40-70%) of pyridine, an aromatic tertiary amine catalyst, is able to promote translation on r ibosomes without the presence of soluble protein factors or chemical e nergy sources, Compared with Monro's fragment reaction [Methods Enzymo l. 20, 472-481 (1971)], which reflects only the peptidyltransferase st ep, this novel translation system can produce polypeptides with chain lengths of at least several tens of residues depending on the template RNA. In the presence of 60% pyridine, poly(U) and poly(UC) promoted i ncorporation of the respective amino acids, phenylalanine and serine-l eucine, twofold, whereas poly(A) promoted the incorporation of lysine by only 25%. The degrees of polymerization of phenylalanine and lysine were up to the decamer and around 40mer, respectively, In poly(UC)-de pendent oligo(serine-leucine) synthesis, oligopeptides with a serine a nd leucine alternate sequence were the main products, This novel pyrid ine system evidently differs from the non-enzymatic translation system reported by Gavrilova and Spirin [FEBS Lett. 17, 324-326 (1971)]; the former system displays partial resistance toward deproteinization rea gents such as SDS and proteinase K, whereas the latter system is compl etely sensitive.