[Biological properties of an asparaginase-glutaminase preparation from Pseudomonas fluorescens in cell cultures]. / Izuchenie biologicheskikh svoistv preparata asparaginazy-gliutaminazy iz Pseudomonas fluorescens v kletochnykh kul'turakh.

Specific L-asparaginase activity and non-specific cytotoxicity of asparaginase-glutaminase preparation from Pseudomonas fluorescens were studied. Two cell lines, i.e. the asparaginase-dependent (Berkitt lymphoma cells) and the asparaginase-independent (the ovary cancer cells) were used as the test-system. Incorporation of 3H-timidine into DNA was used as the criterion of the drug effect on the cells. Krasnitin was used as the reference preparation. The preparation of asparaginase-glutaminase was inferior to krasnitine by its specific antitumour asparaginase activity and superior to it by the general cytotoxicity in the cells of CaOv. With the help of the above test-system it is possible to study the specific asparaginase activity of the drugs containing L-asparaginase. For studying the specific glutaminase properties it is necessary to develop another cell test-system.

[Relationship between the effectiveness of the antitumor action of sarcolysine and the latency period between transplantation and tumor appearance]. / Effektivnost' protivoopukholevogo deistviia sarkolizina v zavisimosti ot vremeni poiavleniia opukholi posle perevivki.

Sarcoma induced with 3-methylcholantrene in mice was transplanted to syngeneic recipients. The latent period of the tumour growth varied from 7 to 26 days. Sarcolysine was injected once when the tumour became palpable. When the tumours were revealed 7 to 8 and 10 to 15 days after the inoculation, the tumour growth inhibition was accompanied by increased survival of mice, particularly marked at the latter period. When the tumours were revealed 17 to 20 or 22 to 26 days after the transplantation, inhibition of the tumour growth was not accompanied by any increase of survival.

[Biological properties of L-asparaginase preparations from E. coli in cell cultures]. / Izuchenie biologicheskikh svoistv preparatov L-asparaginazy iz E. coli v kletochnykh kul'turakh.

Non-specific cytotoxicity and specific antitumor activity of 5 preparations of L-asparaginase from E. coli were studied. Two cell line, i.e. the asparagine-dependent (Berkitt lymphoma cells) and asparagin-independent (human ovary cancer cells) were used as the test-system. Incorporation of 3H-thimidine into DNA was the criterion of the preparation effect on the cells. Preparation I with the specific activity of 60-90 IU per 1 mg of protein obtained at the first stages of purification had high non-specific cytotoxicity. Preparation II obtained after further purification of preparation I, as well as preparation II without any stabilizer with the specific activity of 200 IU/mg were not inferior to the "Bayer" preparation by their biological properties. Addition of L-asparaginase to the preparation as a stabilizer of excessive glycine (preparation IV) increased its non-specific cytotoxicity and interfered with the study of its properties in the cell systems. Mannitol (preparation V) had no effect on the biological activity of L-asparaginase preparation.

[Cellular test system for studying the biological properties of preparations with L-asparaginase activity]. / Kletochnaia test-sistema dlia izucheniia biologiche skikh svoistv preparatov s L-asparaginaznoi aktivnost'iu.

L-Asparaginase sensitivity and asparagin-deficiency of 5 tumor cell populations, i.e. mouse lymphoma L-1210, LI0-1, LTL, Berkitt lymphoma and human ovary cancer, line CaOv were studied. Radiometric estimation of 3H-thimidine incorporation into the cells of DNA served a criterion of cytotoxicity. "Krasnitin" (FDR) was used as L-asparaginase. The cells of leukemia L-1210, lymphosarcoma LIO-1 and line CaOv were asparagine-independent and non-sensitive to L-asparaginase. The cells of mouse lympholeukemia LTL and the cultures of Berkitt human lymphoma proved to be asparagin-dependent and highly sensitive to L-asparaginase. In concentration of 50 IU/ml the drug inhibited incorporation of 3H-thimidine in the cells of LTL and Berkitt lymphoma by 97-98 and 75-80 per cent respectively. Inhibition of 3H-thimidine incorporation in the cells of LTL and Berkitt lymphoma was more pronounced after incubation with the drug for 8 and 24 hours respectively. Two out of the 5 tumor cell populations were chosen as a result of the study. One of these 2 populations, i.e. the cells of Berkitt lymphoma was asparagin-dependent and highly sensitive to L-asparaginase, the other, i.e. the cells of line CaOv was asparagin-independent and resistant to the specific antitumor effect of the enzyme. The use of a system of these two cell lines provided estimation of the ratio of the specific cytostatic (antitumor activity) and non-specific cytostatic properties in the preparations with L-asparaginase activity.

[Purification and properties of L-glutamine and L-asparagine deaminase from Pseudomonas aurantiaca IBPM-14]. / Ochistka i svoistva dezamidazy L-glutamina i L-asparagina iz Pseudomonas aurantiaca IBFM B-14

An enzymic preparation of L-glutamine and L-asparagine deamidase was obtained from Pseudomonas auractiaca IBPM B-14. The preparation was purified 100--150-fold by thermal treatment and chromotography on columns with biogel P-150 and DEAE-cellulose. The enzymic activity was measured by the methods of hydroxylaminolysis and direct nesslerization. The deamidase preparation had an activity of 51 i. u. by glutamine and 15 i. e. by asparagine. Evidence on the pH effect on the deamidase activity was accumulated.