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A L Shvartsman

Publications and source records attributed to A L Shvartsman.

At least 19 recordsLinked to original sources
PubMed2006

Role of the C-terminal fragment of human transthyretin in abnormal fibrillogenesis.

Polypeptide chain fragments of recombinant transthyretin (TTR) with leucine-55 substituted by proline (L55P), which are involved in abnormal fibrillogenesis of this protein, were studied. No fibrils were produced in purified preparations of TTR(L55P) under the optimum conditions for fibrillogenesis but in absence of protease inhibitors. The ability of TTR for fibrillogenesis was lost because of a limited proteolysis resulting in detachment of the TTR polypeptide chain C-terminal fragment of approximately 18 amino acid residues in length. This proteolysis seemed to occur with involvement of a bacterial serine endopeptidase sohB (EC 3.4.21), which was identified in TTR preparations by the MALDI-TOF method. The presence of the C-terminal fragment of the TTR polypeptide chain seems to be crucial for production of abnormal fibrils.

Amino Acid Sequence↗
PubMed1995

[Molecular heterogeneity of familial hypercholesterolemia in the St. Petersburg population].

Inheritance of Taq I, BstE II, and Nco I restriction fragment length polymorphisms (RFLP) in three families from St. Petersburg with familial hypercholesterolemia (FH) was studied. In two of these families, polymorphic markers of the low density lipoprotein receptor (LDLR) gene cosegregated with the disease. This data confirmed FH diagnosis based on the analysis of blood plasma lipid levels. Three different RFLP haplotypes were associated with the disease, suggesting the presence of at least three point mutations in the LDLR gene in the population studied, i.e., suggesting molecular heterogeneity of FH in the St. Petersburg population.

Adolescent↗
PubMed1995

[A multiexon deletion in the human low density lipoprotein receptor gene as a reason for familial hypercholesterolemia].

Inheritance of Taq I, BstE II, and Nco I restriction fragment length polymorphisms (RFLP) in three families from St. Petersburg with familial hypercholesterolemia (FH) was studied. In two of these families, polymorphic markers of the low density lipoprotein receptor (LDLR) gene cosegregated with the disease. This data confirmed FH diagnosis based on the analysis of blood plasma lipid levels. Three different RFLP haplotypes were associated with the disease, suggesting the presence of at least three point mutations in the LDLR gene in the population studied, i.e., suggesting molecular heterogeneity of FH in the St. Petersburg population.

Exons↗
PubMed1993

[The modelling of the genetic correction of familial hypercholesterolemia by creating cellular clones stably expressing the human low-density lipoprotein receptor].

The stable expression of human low-density lipoprotein receptor (rLDL) was studied in Chinese hamster ovary (CHO) cells transformed by the pMSVL recombinant plasmid. This plasmid contains full-length rLDL cDNA and hybrid promoter consisting of regulatory elements from early SV-40 promoter and glucocorticoid responsive enhancer of Moloney sarcoma virus. The expression of rLDL cDNA in transformed cells was demonstrated using RNA-cDNA blot hybridization, PCR analysis, and immunofluorescent analysis.

Animals↗
PubMed1990

[Polymorphism of nucleotide sequences of human genomic DNA linked to a mucoviscidosis locus].

Polymorphism in the restriction fragments length of human DNA sequences linked to mucoviscidosis locus was studied in the healthy control group and in the families affected by mucoviscidosis. The plasmid clones metH, pJ3.11,XV-2c and pKM.19 were used as hybridization probes. The allelic frequencies of the polymorphic loci were determined for total population and for affected families. The linkage disequilibrium between the disease locus and linked polymorphic loci detectable with XV-2c (TaqI endonuclease) and pKM.19 (PstI endonuclease) was demonstrated. The high informational value of DNA-diagnosis of mucoviscidosis in the family studies with the use of four DNA probes combination has been demonstrated.

Cystic Fibrosis↗
PubMed1990

[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. After in vivo pulse labeling, the newly formed radioactive Cp was detected in the membrane fractions from all these organs. The newly formed Cp was concentrated within the membranes of the Golgi complex of various organs where it was revealed by different immunochemical techniques. Experiments with isolation of the liver from the systemic circulation showed that the liver is the only organ secreting Cp into the blood stream. It was suggested that mammalian tissues contain at least two molecular forms of Cp, i. e., circulatory and intracellular ones.

Animals↗
PubMed1988

[Mapping of apolipoprotein A-1 and ceruloplasmin genes on human, rat and mouse chromosomes by hybridization in situ with specific human DNA probes].

In situ hybridization was carried out on metaphase-prometaphase chromosomes of PGA-stimulated lymphocytes and bone marrow cells obtained from laboratory rats and mice. Plasmid cloned sequences of human apolipoprotein A-1 (Apo A-1) and ceruloplasmin (CP) cDNA fragments have been used as specific probes labelled in nick-translation reaction with 3HdTTP and 3Hd ATP. The data of our study suggest that Apo A-1 is localized in 11q14-22, 9 A2-4 and 5q36 areas in men, mice and rats, respectively. The DNA sequences of human CP cDNA most probably occupy 3q23-25, 13q24-26 and 15q13-20 areas. Heterologous in situ hybridization of other species with DNA probes does not always give reliable results in gene mapping. Thus, the data of heterologous hybridization should be considered with caution.

Animals↗
PubMed1985

[Mapping of the ceruloplasmin gene on human and laboratory mouse chromosomes by direct in situ hybridization].

Mapping of ceruloplasmin gene in human and mouse chromosomes was carried out using the cloned fragments of rat chromosomal ceruloplasmin gene and of ceruloplasmin cDNA as specific hybridization probes. DNA probes were nick-translated with 125I-dCTP up to the high specific capacity. The number of silver grains as well as their distribution along the differentially stained chromosomes were analyzed in 120 metaphase plates from bone marrow cells of laboratory mice and in 181 plates from human lymphocyte cultures. The most probable localization of human ceruloplasmin gene is centromeric region q11-13 of chromosome 15(14?). In laboratory mice ceruloplasmin gene is assigned to the euchromatic part of D-disc of chromosome 9. The possible causes for gene synteny in laboratory mouse and in man as well as its evolutionary implication are discussed.

Animals↗
PubMed1985

[Use of specific DNA probes for mapping the ceruloplasmin gene on rat chromosomes by direct in situ hybridization].

Specific DNA-probes representing the fragments of chromosomal ceruplasmin gene (lambda RCp-1, lambda RCp-2, lambda RCp-3) and its cDNA copy of the corresponding mRNA were heavily labelled with 125J dCTP (the specific activity of the probes varying from 1.5 X 10(7) to 3.4 X 10(8) dpm). These probes were used for in situ hybridization on metaphase chromosomes. The total number of silver grains and their distribution along differentially stained chromosomes were determined in 653 metaphase plates from bone marrow cells of laboratory rats. The results of in situ hybridization were very similar for all four specific DNA-probes tested and allow to assign ceruplasmin gene to the q13 region of chromosome 7. The local increase of silver grain count over chromosome 15 was also registered and discussed.

Animals↗
PubMed1984

[Mapping of the transferrin gene in laboratory rats, mice and man by direct in situ hybridization].

Mapping of the gene coding for transferrin was carried out in metaphase chromosomes from bone marrow of laboratory mice and rats as well as from PHA-stimulated human lymphocytes using direct in situ hybridization technique. Plasmid pRTf-17 carrying the insert of rat transferrin cDNA was nick-translated with [125I]dCTP and used as a specific hybridization probe. The total number of silver grains and their distribution along differentially stained chromosomes were determined in 464 metaphase plates (114, 263 and 87 from rat, mouse and man, respectively). The data obtained enable us to assign transferrin gene to chromosome 3 in human and chromosome 9 in mouse. For the first time, the rat transferrin gene was localized on chromosome 7. The most probable sites of transferrin gene localization are 7q31-34, 9F1-3 and 3q21 in rat, mouse and human chromosomes, respectively.

Animals↗
PubMed1982

[Molecular defect of ceruloplasmin synthesis and maturation in Wilson-Konovalov disease].

The radioimmunochemical study of ceruloplasmin-synthesizing polyribosomes was carried out using bioptic liver specimens obtained from fourteen homozygous patients with hepatolenticular degeneration (Wilson--Konovalov disease) and from eight control patients with various non-hereditary diseases. The measurement of binding of 125I-antibodies to the nascent polysome-bound ceruloplasmin chains demonstrated that in control patients this protein is only synthesized on membrane-bound polysomes, while free polysomes do not contribute to the synthesis of ceruloplasmin. The majority of homozygous carriers of Wilson--Konovalov mutation (eleven of fourteen) are characterized by the involvement of free, rather than membrane-bound polysomes, in the synthesis of ceruloplasmin. This shift of ceruloplasmin synthesis from membrane-bound to free polysomes seems to be accompanied by disturbances in the cotranslational proteolytic maturation of ceruloplasmin from its biosynthetic precursors. As a result of this defect, a putative of ceruloplasmin (preproceruloplasmin) was detected in the content of Golgi complex as well as in the serum of homozygous patients. This precursor of a molecular weight 84,000 was found neither in Golgi complex, nor in the serum of control subjects.

Adult↗
PubMed1978

Physicochemical properties and isoenzyme composition of hexokinase from normal and malignant human tissues.

The activity of hexokinase was studied in several normal and malignant human tissues. The enzyme activity in tumors was significantly higher. Isoenzyme studies on normal gastric mucosa and stomach cancer extracts showed that malignancy is accompanied by a "simplification" of the hexokinase isoenzyme pattern due to "deletion" of the slowest isoenzyme. Preparative polyacrylamide gel electrophoreis was used to isolate hexokinase isoenzymes from normal and malignant tissues. Tumor hexokinase isoenzymes displayed an increased affinity to glucose when compared to the corresponding normal prototypes (Km/glucose, 10(-6) M and 10(-5) M, respectively; Km = Michaelis constant). The molecular weights, subunit composition, and peptide patterns were identical for corresponding isoenzyme pairs from normal and tumor tissues.

Female↗
PubMed1978

[Tumorous origin of the hexokinase in human biological fluids].

Hexokinase of the endometrium and gastric mucosa is represented by 5 isoenzymes. The "simplification" of HK isoenzyme spectrum is characteristic of cancer tissue. So, in gastric cancer there is a disappearance of the "slowest" isoenzyme, while in malignant endometrium the "fastest" one was absent. Hexokinase isoenzymes of the serum were identical to those in the tumors in question, that indicates the tumor origin of the body fluid hexokinase. The latter was not observed in normal body fluids. The isoenzymic composition of hexokinase in uterine fibromyoma did not differ from that in normal tissues. If hexokinase appeared in the serum of these patients, its isoenzymic composition was similar to that in the normal uterus. The study on the hexokinase isoenzyme composition may be a valuable adjunct in establishing the differential diagnosis between benign and malignant tumors.

Body Fluids↗
PubMed1976

[Identification of hexokinase synthesizing polyribosomes in human normal and tumor tissues].

Comparative study of concentrations of growing hexokinase subunits polypeptide chains in the polyribosomes from normal and tumour human stomach tissue is studied using specific antiserum to hexokinase isoenzyme from human stomach tumour tissue. It is shown by two different methods (chromatography on Sepharose 46 and sucrose concentration gradient analysis) that the content of hexokinase polypeptides in stomach tumour is several times higher than in homologous normal tissue. The acta obtained show that the high activity of hexokinase in tumour tissues is due to the increased synthesis rate of the enzyme.

Hexokinase↗