Isolation and partial characterization of molecular forms of ceruloplasmin from human bile.

Highly purified ceruloplasmin (CP) was isolated from human bile using affinity chromatography. Biliary CP is represented by two molecular species. One of those is identical to oxidase CP from normal human serum while the other is analogous to oxidase-lacking CP specific for the serum of the carriers of Wilson's mutation with respect to immunological specificity, electrophoretical mobility and molecular mass of the large fragments from spontaneous proteolysis.

[Interaction of molecular forms of ceruloplasmin with specific membrane receptors from healthy persons and patients with hepatolenticular degeneration].

The ceruloplasmin (CP) interaction with the specific receptor localized on the erythrocyte membrane of healthy donors and of patients with hepatolenticular degeneration (HLD) was studied by using Scatchard analysis. It was found that in patients with the Wilson's disease the CP receptor is unaffected by the pathological process. The molecular mass of the erythrocyte receptor of CP is about 130 kDa.

[Various properties of the ceruloplasmin receptor, isolated from human erythrocyte membranes].

An electrophoretically pure preparation of ceruloplasmin (CP) receptor which retains its ability to bind to CP was isolated from human erythrocyte membranes. It was found that in terms of molecular mass, number and size of spontaneously proteolytic fragments as well as antigenicity, the CP receptor molecule strongly resembles that of CP. A comparative analysis of two-dimensional peptide maps of full tryptic digests of the both protein revealed that about 30% of CP peptides are identical in respect of their electrophoretic and chromatographic mobilities which points to the genetic independence of these proteins.

[Biosynthesis of ceruloplasmin in various rat organs].

Ceruloplasmin (CP) biosynthesis in various organs of the rat was studied. It was found that the translation products of postmitochondrial extracts of various organs of the rat contain immunoreactive polypeptides of CP. In respect of proteolytic fragments formed during the digestion with staphylococcal protease V8, these polypeptides do not differ from one another.

[Expression of ceruloplasmin gene in various organs of the rat].

The contribution of different rat organs to the synthesis of ceruloplasmin (Cp) was studied. Dot hybridization with the use of the Cp cDNA probe revealed Cp mRNA sequences in RNA preparations from liver, heart, kidney as well as from different divisions of brain, the concentration of Cp mRNA sequences being maximal in the liver. Polyribosomes isolated from these organs effectively synthesized Cp in a cell-free system derived from rabbit reticulocytes.