Calcium stimulation of polyphenylalanine synthesis in a bovine heart cell-free system

A bovine myocardial cell-free system, active in polyphenylalanine synthesis, has been studied. When Ca²⁺ was present under suboptimal Mg²⁺ concentrations (2 and 5 mM) a marked stimulation of the poly(U) directed macromolecular synthesis was obtained. Calcium did not stimulate the aminoacylation of bovine heart tRNA^Phe The evidence suggests that calcium is required, in conjunction with other cations, for an efficient translation of synthetic polynucleotides.