Structural and functional characterization of the abnormal Z alpha 1-antitrypsin isolated from human liver

alpha 1-Antitrypsin has been isolated from liver inclusion bodies of a subject with a homozygous Z deficiency. The inhibitor was recovered in a fully active form by extraction in high salt at either pH 2.0 or pH 8.0. Carbohydrate analysis indicated a protein in the 'high mannose' form, and this was collaborated by its sensitivity to endo-beta N-glucosaminidase. These data suggest that the abnormal alpha 1-antitrypsin is blocked in the secretory pathway prior to its entrance into the Golgi, and that this blockage is not due to a gross misfolding of the polypeptide.