Xenopus oocytes can synthesise but do not secrete the Z variant of human α1‐antitrypsin

Abstract
Human liver mRNA was prepared from a patient homozygous for α1-antitrypsin deficiency (PiZZ) and from a normal subject (PiMM). Both liver RNAs were microinjected into Xenopus oocytes and α1-antitrypsin identified by immunoprecipitation. The normal M variant of α1-antitrypsin is synthesised and secreted by Xenopus oocytes, the abnormal Z protein is not secreted and an intracellular form accumulates in the oocytes. In the presence of tunicamycin an unglycosylated form of M α1-antitrypsin appears in the incubation medium but no corresponding unglycosylated version of the Z protein is secreted.