A RELATIONSHIP OF <i>N</i>‐ACETYLASPARTATE BIOSYNTHESIS TO NEURONAL PROTEIN SYNTHESIS¹²

Abstract

Abstract— A detailed time study of the incorporation of label from sodium‐[1‐ 14 C]acetate, [1‐ 14 C]ethanol, and [2‐ 14 C]glucose into the aspartyl moiety of N ‐acetylaspartic acid (NAA) was conducted. As expected the specific activity of aspartate increased rapidly with time and peaked within 15‐20 min after which it fell sharply; but significantly, that of the aspartyl moiety of NAA rose very slowly even after the specific activity of aspartate had fallen to less than 1 per cent of the peak values. A rat brain microsomal free supernatant preparation was shown enzymatically to incorporate label from sodium‐[1‐ 14 C]acetate into the t‐RNA fraction from which was isolated N ‐[1‐ 14 C]acetylaspartic acid. From these observations we were inclined to speculate that NAA‐t‐RNA may serve as an initiator of neuronal protein synthesis.