Biotechnologia Acta

9-20

Authors: S. V. Prylutska

The literature data and own research results concerning antitumor effect in vitro and in vivo of C60 fullerene and its derivatives, cytostatics, and conjugated systems on their basis, which enable the practical application of C60 in combined chemotherapy for treatment efficacy improving of malignant tumors are generalized. The mechanism of antitumor action of C60 fullerene in combined treatment with cytostatics is based on antioxidant properties of its molecule, thereby reducing toxic side effects of traditional drugs in a body and ability to their transport purposefully into the target cells. The unique structure of C60 enables to modify its surface with chemotherapeutic drugs. Under combined action of the "fullerene C60-chemotherapy drug" conjugate the anti-tumor effects enhancement is observed both in vitro and in vivo, namely quantity reduction of viable tumor cells, tumor reduction etc. Furthermore, protective effects of fullerene C60 and derivatives relatively toxic effects of chemotherapeutic agents in a body were observed. Conjugate auxesis empowers it to be kept longer in a cell and prolong the duration of drug action. Ability of fullerene C60 to selective accumulation provides its using for target drug delivery.

33-42

Authors: E. I. Yusova

The purpose is to study the plasminogen-activating activity of 36 kDa-streptokinase fragment, influences of desAB-fibrin on this process and low molecular weight streptokinase on plasmin catalytic properties as well. The 36 kDa-fragment lacking the 63 N- and 34 C-terminal amino acid residues was obtained by preparative electrophoresis from chymotrypsin hydrolyzate of the native streptokinase. It was shown that 36 kDa streptokinase activates Glu-plasminogen in solution only at high concentrations of reacting components (2•10-7M). Activation process begins after a long lag-period and is in 100 times slower compared with the native streptokinase. Lys-plasminogen, mini-plasminogen (Val442-plasminogen) but not its Glu-form are activated at definitely lower protein concentrations (5•10-8M), while the reaction rate with mini-plasminogen is order of magnitude greater as compared with Lys-plasminogen and is equal to 4,3•10-2 and 5•10-3 o.u./min respectively. DesAB-fibrin increases efficiently the rate of Glu- and Lys- plasminogen activation by 36 kDa-streptokinase and practically has no effect on the rate of mini-plasminogen activation. Low molecular weight streptokinase has no influence on amidase and fibrinolytic activity of plasmin and does not protect the enzyme from inhibitory effect of α2-antiplasmin. In the presence of the streptokinase fragment, plasmin showed no its activator activity towards plasminogen. A conclusion is made, that during plasminogen activation by low molecular weight streptokinase in the presence of desAB fibrin, a certain site of the fibrin molecule acts as N-terminal peptide of the native streptokinase, inducing conformational changes in proenzyme. These changes are necessary for quick complex formation with 36- kDa streptokinase and formation of the active centre in proenzyme molecule by this form of streptokinase.

52-59

Authors: T. V. Shkand, A. D. Roshal, N. A. Chizh, A. S. Varenikov, V. O. Cheranovsky, B. P. Sandomirsky

Dependence of rheological and diffusion properties of gels on their composition as well as desorption of active components from the resulted implants in biological objects have been studied. The work has been performed in vitro using step-wise extraction of polypeptides form the heart of newborn piglets and also in vivo by implanting the «gel-extract» complex into muscular tissue of rats. The dynamics of peptide transfer was assessed using photometric and fluorometric methods. It has been established that with the growth of alginate concentration in gel there is a transition from convective mechanism of mass transfer to molecular diffusion. The study of the dynamics of mass transfer of fluorescent protein (R-phycoerythrin) has shown that peptides release from a gel into surrounding tissues for 5 hrs with the rate of 8‒9% per hours with following decrease in the extraction rate due to cross diffusion, which contributes to prolonged effect of peptides to a target organ. Thus the data presented about mass transfer in alginate gels should be taken into account when designing the compositions of «peptide-extract gels» during transplantation into biological objects.

69-73

Authors: S. S. Dekina, I. I. Romanovska, A. M. Ovsepyan, A. L. Molodaya, І. І. Pashkin

The lysozyme immobilization in cryogel of polyvinyl alcohol and physico-chemical properties of obtained preparation was investigated. Hydrolytic activity of lysozyme was determined by bacteriolytic method, using Micrococcus lysodeikticus cells acetone powder as substrate. Protein content was determined by the Lowry–Hartree method. Immobilization of lysozyme was conducted by entrapment in polyvinyl alcohol gel with subsequent cycles of freezing-thawing. Antimicrobial activity was studied by standard disk-diffusional method. The hydrogel filmic coatings with antimicrobial action, insoluble at physiological conditions, with quantitative retaining of protein and hydrolytic activity of lysozyme were obtained. The product is characterized by the widened pH-profile of activity at acidic pH values, stability in acidic medium (pH 5.5) and at storage. Its antimicrobial action against Staphylococcus aureus ATCC 25923 F-49, Pseudomonas aeruginosa 415, Escherichia coli 055 K 59912/4 and Candida albicans ATCC 885-653 was noted. The proposed method of lysozyme immobilization allows to obtain stable, highly effective product with antimicrobial activity, prospective for usage in biomedical investigations.

81-87

Authors: T. I. Halenova, M. Y. Kuznetsova, O. M. Savchuk, L. I. Ostapchenko

The insulin receptor was isolated from the liver cell membranes of control and diabetic rats. The protein purity was controlled by electrophoresis and Western blot. The tyrosine kinase activity of the insulin receptor was investigated in the incubation medium in the presence of insulin (concentration range: from 10-11 M to 10-5 M). The basal tyrosine kinase activity of the insulin receptor (in the absence of insulin) was equal for the control and diabetic state. Maximal tyrosine kinase activity of the diabetic and control insulin receptor was observed at the insulin concentration of 10-8 M. Results indicate that type 2 diabetes did not cause the irregularities in the functioning of the insulin receptor that could be the reason of insulin resistance.

95-101

Authors: G. S. Andriiash, G. M. Zabolotnа, S. М. Shulga

Strains-producers of essential amino acids of aspartate family such as Corynebacterium glutamicum, Brevibacterium flavum, Brevibacterium sp. 90, Brevibacterium sp. 90H, Brevibacterium sp. E531 from «Collections strains and lines of plants for food and agricultural biotechnology» of «Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine» for biosynthetic activity for lysine and threonine were investigated. Active strains-producers of amino acids were obtained after UV irradiation, biological characteristics of these organisms were studied and their biosynthetic efficiency was estimated. New mutant strains of threonine and lysine were selected using analysis of regulatory and analogorezistent auxotrophy. Sensitivity of output and mutant strain-producers to penicillins, macrolides, cephalosporins, tetracyclines, and other groups of antibiotics was investigated. Biosynthetic activity of obtained threonine producers – Brevibacterium flavum IMВ B-7446 and lysine – Brevibacterium sp. IMВ B-7447 on the production of target amino acids was determined. Strains are deposited in the «National Depository microorganisms» of the Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine.

108-114

Authors: B. Zarei Darki, О. N. Кorol, R. G. Gevorgiz

Extreme daily productivity values of microalgae culturing system with different orientation of the illuminated surface and under natural light were assessed. Calculations are made for natural light conditions around neighborhoods of Isfahan City (Iran). It is shown that if the efficiency factor of photosynthesis equals to 5%, limit values of productivity will be 38 grams of dry biomass per 1 m2 of illuminated surface and 114 grams will be at efficiency of 15%. On basis of simple model understandings regarding the daily distribution of solar radiation, which arrives at the surface of the Earth, productivity of microalgae culturing system for its various orientations relative to the Sun at different photosynthetic efficiency was calculated during the summer half-year (from March 21 to September 21). It is shown that the limit (optimal) value of the yield at the efficiency of 15% will be about 18.5 kg of dry biomass per square meter of illuminated surface. The results can be used to develop technologies for the production of industrially important compounds from microalgae.