[Age-related features of ceruloplasmin biosynthesis and distribution in rats]. / Vozrastnye osobennosti biosinteza i raspredeleniia tseruloplazmina v organizme krys.

Biosynthesis of ceruloplasmin, a copper-containing glycoprotein, which plays an important role in copper transfer and bidirectional iron transport in vertebrates, was studied in 7-day old rats characterized by the embryonic type of copper metabolism. In addition to the liver, copper is synthesized in the lungs, brain, and kidneys. The appearance of labeled ceruloplasmin in the blood flow coincides with the time of liberation of de novo synthesized ceruloplasmin from the liver. [14C]-Ceruloplasmin is absorbed from the blood flow by cells of the heart, lung, and kidneys and binds to erythrocytes. The polypeptide ceruloplasmin chain does not enter the brain cells from the blood flow. Immunoreactive polypeptides of the ceruloplasmin receptor were found using immunoblotting in plasma membranes of the heart, liver, kidneys, and erythrocytes, rather than in those of the brain. It was shown by reverse transcription coupled with PCR using selective primers these cells contain molecular forms of ceruloplasmin mRNAs programming the synthesis of both secretory ceruloplasmin and ceruloplasmin connected with the plasma membrane via the glycosyl phosphatidylinositol anchor. After transition to the adult type of copper metabolism, the blood serum contents of copper and ceruloplasmin sharply increase, while the content of CP in the cerebrospinal fluid, as measured according to the oxidase and antigen activities, and copper concentration, as determined by atom-absorption spectrometry, remain low. Ontogenetic features of the system ensuring the copper homeostasis in mammals are discussed.

[Identification of a fragment of ceruloplasmin, interacting with copper-transporting Menkes ATPase]. / Identifikatsiia uchastka tseruloplazmina, vzaimodeistvuiushchego s med'transportnoi ATP-azoi Menkesa.

The interaction was studied of ceruloplasmin (Cp, EC 1.16.3.1), a copper-containing plasma protein, with two synthetic peptides P15 and P16 whose structures correlate with those of the noncytosolic regions of the copper transfer P1 type ATPase (ATP7A), apparently encoded by the Menkes disease gene (Atp7a). Pentadecapeptide P15 and hexadecapeptide P16 were synthesized using the solid phase method. They correspond to fragments of two extracellular loops ATP7A, of which one loop is apparently involved in the copper ion transfer (P16) whereas the other is not (P15). The protein footprinting showed that P16 binds to a fragment of the ceruloplasmin domain 6. Kinetics of the ceruloplasmin-P16 binding was studied by affinity chromatography on P16 immobilized on a macroporous disk, and the Kd value (1.5 x 10(-6) M) of this interaction was determined. The ATP7A involvement in the copper ion transfer to nonhepatocyte cells is discussed.

[Effects of infant formula feeding on the distribution of copper in the body of 8-day-old rats]. / Vliianie iskusstvennogo vskarmlivaniia na raspredelenie medi v organizme 8-dnevnykh krysiat.

The oxidase activity of ceruloplasmin (Cp, EC 1.16.3.1), the content of immunoreactive Cp and copper ion concentration were measured in the serum of eight day-old rats receiving either breast feeding (control group) or commercial nutritive mixture which has been recommended for the newborn children beginning from zero age (experimental group). It was shown that the artificial feeding caused almost 3-fold increase of Cp oxidase activity and copper content in the serum when compared to age-matched controls. No changes in the copper content per Cp molecule were observed. Dot-hybridization of the total liver polyribosomal RNA with Cp [32P]cDNA showed that the increased Cp level in the blood of the rats of experimental group correlated well with the level of expression of Cp gene. The copper content in the liver of experimental rats was two times lower that in control animals while no differences was found in the brain copper content between two groups of rats. The role of the regulation of Cp gene expression in the lactating mammary gland and of milk Cp in the copper homeostasis in the newborn body is discussed.

[An optical sensor for analyzing the flow of biological particles in chromatographic processes]. / Opticheskii datchik dlia analiza potoka biologicheskikh chastits v protsessakh khromatografii.

The design of an optic flow sensor operating in the UV spectrum is described. The sensor is intended to monitor changes in the size and/or concentration of light-diffusing particles against the background of low-molecular admixtures, as well as for analysis of these admixtures. The sensor has been employed in gel chromatography and adsorption chromatography of virus-containing suspensions.

[Functions of the late genes 13, 17, 18 and 19 in pi8 phage]. / Funktsii pozdnikh genov 13, 17, 18 i 19 faga pi8.

Genes of the right arm of the pi80 phage chromosome were characterized by studying lytic and antigenic activities and replication ability of mutant phages and by electron microscopic examination of their lysates. It is shown that the genes 14, 15 and 16 are early, and the genes 17, 18 and 19 are late. The functions of four genes are determined. The gene 13 is responsible for antigenic activity and for phage host-cell specificity; the gene 17 is a regulator of the late functions; the gene 18 product affects the cell membrane; the gene 19 controls the synthesis of phage endolysine. It is suggested to redesignate the pi80 phage genes 13, 17, 18 and 19 by the letters J, Q, S and R respectively, because these genes fulfil the same functions as the lambda genes J, Q, S and R.

[Mapping of the c-region of phage phi80]. / Kartirovanie c-oblasti faga phi80.

A set of c-mutants of the phage phi80 is isolated. These mutants fit into three genes. According to plaque morphology and frequency of lysogenization of mutants, the genes were named cI, cII and cIII as it was previously done for phage lambda. Their order, determinated by mutant phage crosses, is cIII-sus326-cI-cII-sus250. Sus326 is a mutation in the gene 15, so it is probably an analogue of the N gene of the phage lambda. Thermoinducible mutants of the phage phi80 cts11 and cts12 correspond to the mutant types cItsB and cItsA of the phage lambda and they complement each other. Thus, it is supposed that phi80 phage repressor molecules consist of few protein subunits.