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M D Lutsik

Publications and source records attributed to M D Lutsik.

At least 37 records · Page 2Linked to original sources
PubMed1976

[Heterogeneity of crystalline antithyroid phytoprecipitin].

The crystalline preparation of antithyroid phytoprecipitin has been resolved by chromatography on Whatman CM-32 cellulose on a preparative scale into two components, designed respectively A and B. Each component was further resolved into consisting polypeptide chains alpha (mol. weight 7.000) and beta (mol. weight 17.000) by gel filtration on sephadex G-50 in 1 M acetic acid 6 M urea. Homologous chains were comparatively studied by electrophoresis in acrylamide gel, amino acid analysis and peptide mapping technique. Electrophoresis in acrylamide gel with 6 M urea according to Takayama [8] revealed the identical mobility of beta chains in both components A and B, while alpha chains differed. alphaA chain was more basic, than alphaB, i.e. it had greater positive sharge. The amino acid analysis and peptide mapping showed that alphaA chain had one residue of lysine more than alphaB chain. The comparison of beta chains by peptid mapping confirmed their complete identity.

Amino Acids↗
PubMedDate not supplied

Electron cytochemical study of carbohydrate components in different types of cultured glial cells of snail Helix pomatia.

Using a variety of colloidal gold-labelled lectins with different sugar specificities, the structure and topography of carbohydrate determinants of the surface membrane of in vitro cultured glial and nerve cells of the snail Helix pomatia have been electron cytochemically studied. Heterogeneity of carbohydrate pools among different types of glial cells and between glial and nerve cells was established. It was found that satellite glial cells having the ultrastructural signs of cells with high metabolic level (type II cells) selectively bind GNA which is specific to terminal alpha-D-mannose residues and do not bind other mannose-specific lectins, Con A and LCA. GNA determinants are absent in satellite type I glial cells, fibrous glial cells, microglia and neurons. It has been found that glial cells (satellite type I and II glial cells, filamentous glial cells and microglial cells) do not bind PVA and LABA. LTA did not bind to any glial cells and binds weakly to neurons. Con A and WGA determinants which are abundant on the neurons are completely absent on satellite type II glial cells but present on satellite type I glial cells and filamentous glial cells. Microglial cells contain Con A and LCA determinants and the density of PNA determinants on these cells is the highest compared to other types of glial cells or neurons. It is concluded that some lectin determinants (for RCA-1, PNA, LPA) are present on all types of glial cells, while another determinant (GNA) is specific for a definite type of glial cells and can serve as a marker of these cells. The role of specific carbohydrate determinants in the functioning of a neuron-glial complex is discussed.

Animals↗
PubMedDate not supplied

[Study of membrane glycoproteins of human erythrocytes using lectins].

A method to study the glycoprotein composition of cell membranes, in particular of human red blood cells, has been developed. It includes the separation of membrane components by the SDS-polyacrylamide gradient slab gel electrophoresis, electroblotting of the phoretograms onto the nitrocellulose sheets and detection of glycoprotein fractions with FITC and peroxidase labeled lectins. PNA detected asialoglycoproteins with O-linked oligosaccharide chains, corresponding to all the PAS-positive bands of the phoretogram. SBA interacted more selectively and revealed only certain PAS-positive bands. Glycoproteins with N-linked carbohydrate chains were PAS-negative and can be identified only by the interaction with WGA, LCL, RCA. Group-specific agglutinins have shown that the ABO antigenic determinants are located in N-linked carbohydrate chains of membrane glycoproteins.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

[Identification and properties of insulin receptors in neuroblastoma C 1300 N 18 cells in various functional states].

The presence of insulin receptors in neuroblastoma C 1300 N18 cells was shown by the method of the [125I]insulin binding with cells as well as by the electron-cytochemical methods based on the analysis of the binding of colloid gold-labelled insulin and of agglutinin of wheat embryos with the surface of plasma membrane. It is established that the number and distribution of insulin receptors depend on the functional state of cells. Expression of receptors on the membrane increases after 5'-deoxyuridine-induced differentiation of cells. Due to changes in the lipid composition of cells caused by the incubation with lecithin-cholesterol liposomes (an increase in the content of cholesterol and its esters, as well as of unsaturated fatty acids and appearance of lysolecithin) the quantity of insulin receptors decreases and cell membranes are damaged. The lowering insulin regulation is not observed for insulin receptors of the neuroblastoma C 1300 N18 cells.

Cell Differentiation↗
PubMedDate not supplied

[A new affinity sorbent for the purification of lectins and its use in the purification of wheat germ agglutinin].

A method is developed for obtaining gel from eggwhite and its application as a sorbent for purification of lectins. Eggwhite was treated by 1% glutaraldehyde at pH 5, for 5-6 hours at room temperature, then it was minced and washed by water. The residual aldehyde groups were blocked by glycine treatment. The sorbent obtained possessed high affinity for lectins specific to N-acetylglucosamine and complex oligosaccharides. The galactose- and mannose-specific lectins were adsorbed to a less extent. The purification of the wheat germ agglutinin using the eggwhite gel is described.

Adsorption↗