Translation of collagen messenger RNA in a cell-free system derived from wheat germ

A cell-free system for synthesizing protein from wheat germ was used to translate the messenger RNA extracted from 16-day embryonic chick calvaria. A part of the product had properties similar to collagenous peptides and served as a substrate for prolyl hydroxylase, an enzyme specific for collagen. The level of potassium was critical for the synthesis of high molecular weight products with properties similar to pro-alpha-chains. The potassium concentration for optimal protein synthesis, as judged by maximum incorporation of [3H]proline into acid precipitable material, was considerably lower than the concentration required for the synthesis of high molecular weight collagenous peptides.