[Modification of the ligand load and structure of human serum albumin with different methods of isolation].

The influence of isolation procedures on physico-chemical properties of human serum albumin (HSA) has been studied using differential scanning calorimetry and infrared spectroscopy. Fractionation of blood plasma with polyethylene glycol (PEG) followed by ion-exchange chromatography produced healthy donor albumin whose melting thermograms were identical to those of the HSA in non-fractionated plasma. The endotherms of HSA samples isolated by affinity chromatography (AC) and native electrophoresis (EP) are bimodal as distinct from monophasic endotherms of PEG-HSA preparations.

[Effect of various specific agents on the heat stability of human serum albumin].

Effect of lipoic acid, 5,5-dithiobis-2-nitrobenzoic acid, monoiodoacetic acid and cystine on thermal stability of human serum albumin was studied by differential scanning calorimetry and electrophoretic methods. Quantitative estimation of the protective effect of these reagents on resistance of 5% solutions of albumin to the temperature influence was studied. It is concluded that all the compounds used protect albumin from polymerization at heating.

[Proliferative activity of normal and tumorous plant tissues cultivated in vitro].

Proliferative pools of Helianthus tuberosus L. explants tissues were studied using autoradiography with 3H-thymidine in the course of normal growth in vitro and tumorous growth induced by Agrobacterium tumefaciens. It is determined that on the 3d or 4th day of tumorous transformation the number of cycling cells reaches 30% whereas that of normally growing explants showed 10-11%.

[Relationship between crown-gall plant tumors and the cell cycle].

It is established that under conditions of the culture in vitro the greatest amount of crown-gall swellings on topinambur and carrot explants is formed with Agrobacterium tumefaciens inoculation 4 and 6 hrs after the tissue extraction and planting, which corresponds to the G1-phase of the 1st cellular cycle. In the inoculated tissue cells entrance to the S-phase is accelerated and the maximal number of labelled nuclei is found 10 hrs earlier.