Вестник МГТУ. 2018, №3.

Вестник МГТУ. 2018. Т. 21, № 3. С. 402–411. DOI: 10.21443/1560-9278-2018-21-3-402-411 411 T. N. Pivnenko, Yu. M. Pozdnyakova, N. N. Kovalev, E. V. Mikheev, R. V. Esipenko The enzymatic activity of various organs and tissues of Far-Eastern trepang as a system of indicators of maturation and quality of products The activity, substrate-inhibitory specificity, temperature and pH dependence, seasonal changes in proteolytic and nucleolytic enzyme systems of the digestive tract, muscle and reproductive trepangs tissues have been considered. The different-rule variability of enzyme activity at different stages of development has been shown. At the stage of growth proteolytic enzymes of the intestinal tract have the greatest activity, which is significantly reduced during spawning. In muscle tissue, there are opposite processes associated with changes in the strength. Separation of proteases of the trepang digestive tract by ion exchange chromatography has been carried out. Two peaks of proteins showing trypsin activity corresponding to the isoforms of this enzyme possessing a negative charge have been detected. The molecular weight of the corresponding peaks determined by the electrophoresis method is 26 and 28 kDa. The data obtained are similar to those established earlier for other types of holothurians. Determination of the activity of proteases of trepang muscle tissue in different seasons has shown a low level of proteolytic activity during the growth period. The activity values in acid and neutral proteases are close to each other. The lowest activity has been detected in alkaline proteases. During the spawning period, the activity of acid proteases increases significantly in the muscle tissue, proteolysis remains at the same level in the neutral and alkaline zone. Reproductive tissue processes of growth and formation of the gonad is accompanied by high activity of the acidic deoxyribonucleases. At the stage of spawning it is significantly reduced, in the post-spawning period it is completely absent. Interactions of enzymes with substrates and inhibitors allow preventing the presence of cathepsins, metalloproteases and serine proteases in the trepang intestinal. The reduction of strength of the muscle tissue may be due to the action of metalloproteases affecting on the structure of the collagen matrix. The results are recommended for the development of rational methods of trepang processing by regulating the activity of enzymes. Key words: holoturia, proteases, nucleases, stages of development, seasonal changes.