PURIFICATION OF ASPARTATE-TRANSCARBAMYLASE FROM DROSOPHILA-MELANOGASTER

A purification procedure is described by which aspartate transcarbamylase was obtained from cultured cells of DDrosophila melanogaster as part of a high‐molecular‐weight enzyme complex. The complex is shown to contain several polypeptides. An antiserum directed against the complex enzyme nihibited in vitro the activity of aspartate transcarbamylase, carbamylphosphate synthetase and dihyro‐orotase which were shown to copurify on a sucrose gradient and by gel electrophoresis. A fast preparation procedure using this antiserum yielded a 220000‐molecular‐weight protein in addition to the polypeptides present in the complex. A purification procedure is also described to obtain aspartate transcarbamylase from second instar larvae of Drosophila. At this stage, the enzyme is not complexed with carbamylphosphate synthetase and dihydro‐orotase but exhibits the same molecular weight as the aspartate transcarbamylase moiety found in the high‐molecular‐weight complex of cultured cells. Copyright © 1978, Wiley Blackwell. All rights reserved