[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.

Molecular forms of ceruloplasmin in hepatolenticular degeneration and their interaction with human erythrocyte ceruloplasmin receptor.

Immunochemical methods were used to show that the sera of homozygous and heterozygous carriers of the Wilsonian gene contain, together with normal ceruloplasmin (CP), a CP-like protein that differs from CP in its enzymatic, immunological, and physicochemical properties. The CP-like protein was isolated from the sera of patients with hepatolenticular degeneration (HLD) by means of affinity chromatography, and monospecific antibodies to this protein were obtained. The presence of an 80 kDa immunoreactive polypeptide specific to the CP-like protein was demonstrated by immunoblotting with antibodies to normal CP and monospecific antibodies to the CP-like protein.

[The spectra of de novo synthesized proteins in the early stages of radiation death of lymphocytes in the rat thymus].

A comparative study was made of the spectrum of thymus cell proteins in the control and gamma-irradiated rats. It was shown that early after irradiation a group of proteins appeared in rat thymus cells which had not been traced, or detected in much lower amounts, in intact cells. Part of those polypeptides were referred to general stressor proteins, the other were specific for the effect of ionizing radiation.