CC BY
0УДК 57-579 Abdirassilova Z.N., Alikulov Z.A.
Abdirassilova Z.N.
2nd year master's student at the Department of Biotechnology and Microbiology L.N. Gumilev Eurasian National University (Astana, Kazakhstan)
Alikulov Z.A.
Ph.D. biol. Sciences, Professor of the Department of Biotechnology and Microbiology L.N. Gumilev Eurasian National University (Astana, Kazakhstan)
STUDY OF MOLYBDENUM CONTAINING ENZYMES OF HERBIVOROUS AND PREDATORY FISH
Аннотация: Mo enzymes are found in almost all animal cells and tissues. Particularly common are the enzymes of the XOs family. All data about Mo enzymes are presented on the basis of experiments conducted using archaea, bacteria, plants, some species of mammals and insects. However, there is still no data on the distribution of Mo enzymes in the internal organs of fish, although there are several works on the isolation of XO from fish liver. We assume that it is this family of enzymes (XOs) that will predominate in the internal organs of fish, and that they may be one of the key enzymes in fish homeostasis.
Ключевые слова: Desulfovibrio gigas, ethylenediaminetetraacetic acid, flavin adenine dinucleotide, adenylated molybdopterin, oxidized nicotinamide adenine dinucleotide.
Molybdenum-containing (Mo enzymes) and tungsten (W enzymes) enzymes share a special conserved metal center (Mo, W), which are coordinated by one or two pyranopterins. The coordination sphere of the metal is supplemented with heteroatoms
(oxygen, and/or sulfur, and/or selenium) in different arrangements [1]. Mo-enzymes are organized into the families of xanthine oxidases (XOs), sulfite oxidases (SOs) and dimethyl sulfoxide reductases (DMSORs) [2]. Being diverse, they can participate in a variety of reactions involving the insertion or abstraction of an atom with various substrates (physiological or not). They catalyze almost exclusively oxidation/reduction reactions. Mo is present in these enzymes as molybdopterin or molybdenum cofactor, where the Mo ion cycles between the oxidation states Mo(VI) and Mo(IV) [2-5].
The highest described position on the study of Mo-enzymes in fish, that is, the lack of data in this area, determines the relevance of this work. The study of this topic has a deep fundamental aspect and has potential for applied research.
Hypothesis: the largest amount of enzymes of the XOs family is found in the liver and this may be due to the large accumulation of Mo in this organ. As is known, the highest concentrations of Mo are found in the liver (0.5-0.7 ^g/g) and kidneys (0.3 ^g/g) of mammals, and in sheep the molybdenum content in whole blood is about 0.02 ^g/ml ( 0.21 ^M/L), but is sensitive to changes in diet [5]. We also assume that the content of Mo enzymes in the liver and kidneys may be higher than in other organs. This organ in fish performs an important filtration function, as in other animals, but its distinctive feature is the participation of the kidneys in the immune response to fish.
In connection with the purpose of this master's thesis, studying the content of various Mo-enzymes in the internal organs of S. glanis using the mutant strain N. crassa nit-1, corresponding tasks were set. In accordance with the objectives, a diagram of the stages of implementing the experiments was created (Figure 1). The work was carried out in accordance with the provided diagram.
Fig. 1. Technological diagram of a coupled aquaponic system [1, 5].
In Figure 1, Qmu = make-up water or new water to the system (l/min), Qfish reuse = reuse of water from plants (l/min), Qfish total = total water flowing through the fish (Qmu + Qfish reuse) (l/min), Qfish waste = water consumption from settling tanks and filter tanks (l/min), Qplant total = inflow to beds (l/min), Qminor = water loss from aquariums due to evaporation, splashing and catching of fish and plants (l/min), Qet = water loss from plant evapotranspiration (l/min), Qmin = water returned to the system from the solids mineralization circuit (l/min), Qplant discharge = water discharged from a system to maintain conductivity or total dissolved solids (L/min) limits.
СПИСОК ЛИТЕРАТУРЫ:
1. Wuebbens M. M., et al. Mechanistic and mutational studies of E. coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis // JBC. -2003. - 278(16). - P. 14523 - 32;
2. Leimkuhler S., et al. Mechanistic studies of human molybdopterin synthase reaction and characterization of mutants identified in group B patients of molybdenum cofactor deficiency // JBC. - 2003. - 278(28). - P. 26127 - 34;
3. Zhang W., et al. IscS functions as a primary sulfur-donating enzyme by interacting specifically with MoeB and MoaD in the biosynthesis of molybdopterin in E. coli // JBC. - 2010. - 285(4). - P. 2302 - 8;
4. Marelja Z., et al. A novel role for human Nfs1 in the cytoplasm: Nfs1 acts as a sulfur donor for MOCS3, a protein involved in molybdenum cofactor biosynthesis // JBC. - 2008. - 283(37). - P. 25178 - 85;
5. Zheng L., et al. Cysteine desulfurase activity indicates a role for NIFS in metallocluster biosynthesis // PNAS. - 1993. - 90(7). - P. 2754 - 8
