[Cultivation of cells on a surface covered by microspheres with coupled histones].

The use of histones for modification of the surface intended for cultivation of cells was studied. The work was carried out on the cell line 293 of human embryonic kidney transformed by adenovirus (Ad5) and on the cell line BALB/3T3 clone A31 of mouse spontaneous transformed embryonic fibroblasts. We analyzed interaction of cells with histones of different types put on a hydrophobic surface or on dextran microspheres with diameters of 1.0 microm. It was shown, that all histones studied possessed adhesive ability, but their complexes consisting of total and core histones rendered the best influence on adhesion, morphology and growth of the cells in culture. Thus, cross-linked conjugates of histones immobilized on microspheres promoted in a greater degree formation of a network of cellular structures due to formation of intracellular contacts and simultaneous interaction of cells with several microspheres. Comparing with BALB/3T3 clone A31 the cell line 293 showed significant increase in proliferative activity in 11 days of cultivation on microspheres covered with cross-linked conjugates of histones. Our investigations have shown that the microspheres covered with cross-linked conjugates of histones can be used in the further at creation of the three-dimensional porous matrices intended for in vitro formation of tissue-like cellular structures in them.

[Synthesis and properties of an affinity adsorbent for purifying neuraminidases of varying origins]. / Sintez i svoistva affinnogo adsorbenta dlia ochistki neiraminidaz razlichnogo proiskhozhdeniia.

Neuraminidases (NA) from Clostridium perfringens, noncholera vibrios and influenza virus were purified by affinity chromatography on Sepharose coupled to para-aminophenyl oxamic acid. Adsorption was carried out at pH 5.5. The effect of elution conditions on purification of NA was studied. The use of the pH gradient enhances 10-fold the purification degree as compared with the pH shift-elution process, 90% of the activity being eluted from the column within a pH range from 6.0 to 6.6. According to the described procedure, electrophoretically homogeneous preparations of NA were obtained from noncholera vibrios and influenza virus.

[Interaction of erythrocytes with aminoalkylagarose]. / Vzaimodeistvie éritrotsitov s aminoalkilagarozoi.

Some properties of aminoalkyl-agarose as a carrier for adsorption immobilization of erythrocytes were being studied. The effect of the hydrophobic spacer on the erythrocyte affinity for the matrix is shown. The erythrocyte adsorption is characterized by a positive cooperativity; the shorter the spacer, the higher is cooperativity.

[Synthesis and study of biospecific sorbents for isolating and purifying L-asparaginase from Escherichia coli]. / Sintez i izuchenie biospetsificheskikh sorbentov dlia vydeleniia i ochistki L-asparaginazy Escherichia coli.

Amino acid and oligoamide derivatives of D-asparagine and L-asparaginic acid (L-asparaginase inhibitors) have been synthesized. An increase in the hydrophobic capacity of the modified inhibitor increases the inhibition constant. Once the modified inhibitor binds with Sepharose 6B, the length of the spacer (a chain of atoms attaching the inhibitor to the polymer matrix) determines affinity of the sorbent for L-asparaginase. On these sorbents affinity shifts from pH optimum of the enzyme activity to pH 4-5. The enzyme of E. coli L-asparaginase has been purified.