Mechanisms of copper incorporation during the biosynthesis of human ceruloplasmin.

摘要: To examine the mechanisms of copper incorporation during ceruloplasmin biosynthesis, we developed methods to resolve and identify apo holoceruloplasmin. The identity holoceruloplasmin was confirmed by oxidase activity staining, immunoblotting, 67Cu-ligand exchange, blotting. Following metabolic labeling human liver lung cell lines with 67Cu, newly synthesized detected in culture media as two species apparent molecular masses 84 79 kDa. Pulse-chase studies demonstrate that exogenous is readily available for into kinetics synthesis secretion are identical. Inhibition N-linked glycosylation did not affect rate or amount incorporated but result a single 68-kDa moiety. Despite differences uptake between linear observed no evidence exchange following biosynthesis. Under conditions studied, accounted less than 5% total secreted each line. data indicate early course biosynthesis process independent carbohydrate addition. This results an conformational change molecule which does secretory protein.