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136 results on '"Arinbasarova, A. Yu."'

3. Autooscillatory Dynamics in a Mathematical Model of the Metabolic Process in Aerobic Bacteria. Influence of the Krebs Cycle on the Self-Organization of a Biosystem

Author

Grytsay, V. I., Medentsev, A. G., and Arinbasarova, A. Yu.

Subjects
Quantitative Biology - Other Quantitative Biology, Nonlinear Sciences - Adaptation and Self-Organizing Systems
Abstract

We have modeled the metabolic process running in aerobic cells as open nonlinear dissipative systems. The map of metabolic paths and the general scheme of a dissipative system participating in the transformation of steroids are constructed. We have studied the influence of the Krebs cycle on the dynamics of the whole metabolic process and constructed projections of the phase portrait in the strange attractor mode. The total spectra of Lyapunov exponents, divergences, Lyapunov's dimensions of the fractality, Kolmogorov--Sinai entropies, and predictability horizons for the given modes are calculated. We have determined the bifurcation diagram presenting the dependence of the dynamics on a small parameter, which defines system's physical state., Comment: 8 pages, 6 figures

Published
2020
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41. Kinetic characteristics of L-lysine α- oxidase from Trichodermacf. aureovirideRifai VKM F-4268D: Substrate specificity and allosteric effects

Author

Krupyanko, Vladimir I., Medentsev, Alexander G., Lukasheva, Elena V., and Arinbasarova, Anna Yu.

Abstract

The present work aims to investigate the kinetic characteristics of homodimer enzyme L-lysine α-oxidase from Trichodermacf. aureovirideRifai VKM F-4268D, taking into account allosteric effects. The enzyme was first shown to reveal positive cooperativeness, h=2.05±0.15. Using additional opportunities of Hill coefficient the value of the Michaelis–Menten constant has been estimated, Km=1.015∙10−5М, indicating high strength of substrate binding to the active site of each subunit. High selectivity and absolute L-stereospecificity of the enzyme were shown. The inhibition of L-lysine conversion by non-cleavable lysine analogs as well as the reaction product was found out to take place. These effects have been evaluated only as the inhibition coefficients (%).A more detailed study of these inhibition effects was complicated because of the cooperativeness of enzyme subunits mentioned above. The kinetic scheme of L-lysine α-oxidase was proposed involving parallel-subsequent action of each of two subunits in the catalytic act.

Published
2017
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43. Enzymatic properties and anticancer activity of L-lysine -oxidase from Trichodermacf. aureovirideRifai BKMF-4268D

Author

Pokrovsky, Vadim S., Treshalina, Helen M., Lukasheva, Elena V., Sedakova, Ludmila A., Medentzev, Alexander G., Arinbasarova, Anna Yu., and Berezov, Temirbolat T.

Abstract

L-Lysine -oxidase (LO) from a novel Trichoderma strain: Trichodermacf. aureovirideRifai shows favorable biochemical and kinetic properties (Kmfor L-lysine of 17.9 µmoll, optimum pH 8.0, high stability) and significant antiproliferative activity both in vitroand in vivo. The molecular weight of LO was determined to be 115–116 kDa; the active dimer consists of two identical 57–58 kDa subunits. LO shows considerable cytotoxicity against the following tumor cell lines: K562, LS174T, HT29, SCOV3, PC3, and MCF7, with the inhibition concentration (IC50) ranging from 3.0×10–6to 7.8×10–2Uml (3.2×10–8to 8.2×10–4mgml). Two human colon cancer xenografts HCT116 and LS174T and breast adenocarcinoma T47D implanted subcutaneously into Balbc nude mice showed high sensitivity to LO with a TCof 12, 37, and 36, respectively (P<0.05). The antitumor efficacy of LO was observed in the absence of pronounced morbidity or toxicity in vivo. Taken together, these data suggest that LO may be considered as an effective anticancer agent for the treatment of solid tumors in vivo. This study presents promising data on the possible application of LO in clinical oncology for patients with colorectal cancer.

Published
2013
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46. Fungal Enzyme l-Lysine α-Oxidase Affects the Amino Acid Metabolism in the Brain and Decreases the Polyamine Level.

Author

Lukasheva, Elena V., Makletsova, Marina G., Lukashev, Alexander N., Babayeva, Gulalek, Arinbasarova, Anna Yu., and Medentsev, Alexander G.

Subjects
POLYAMINES, FUNGAL enzymes, BRAIN metabolism, ESSENTIAL amino acids, SECONDARY metabolism, TRICARBOXYLIC acids, INTRAVENOUS injections, AMINO acid metabolism
Abstract

The fungal glycoprotein l-lysine α-oxidase (LO) catalyzes the oxidative deamination of l-lysine (l-lys). LO may be internalized in the intestine and shows antitumor, antibacterial, and antiviral effects in vivo. The main mechanisms of its effects have been shown to be depletion of the essential amino acid l-lys and action of reactive oxidative species produced by the reaction. Here, we report that LO penetrates into the brain and is retained there for up to 48 h after intravenous injection, which might be explained by specific pharmacokinetics. LO actively intervenes in amino acid metabolism in the brain. The most significant impact of LO was towards amino acids, which are directly exposed to its action (l-lys, l-orn, l-arg). In addition, the enzyme significantly affected the redistribution of amino acids directly associated with the tricarboxylic acid (TCA) cycle (l-asp and l-glu). We discovered that the depletion of l-orn, the precursor of polyamines (PA), led to a significant and long-term decrease in the concentration of polyamines, which are responsible for regulation of many processes including cell proliferation. Thus, LO may be used to reduce levels of l-lys and PA in the brain. [ABSTRACT FROM AUTHOR]

Published
2020
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