Thermostability of Lactate Dehydrogenase in Rat Brain under Conditions of Short-Term Moderate Hypothermia
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Thermostability of rat brain lactate dehydrogenase (LDH) was studied in intact animals and animals subjected to moderate short-term hypothermia. Two exponential stages, rapid and slow, were distinguished in the thermodenaturation kinetics. The contribution of the rapid phase to the lactate dehydrogenase denaturation kinetics was more significant: the energy of activation for this phase was 2.33 times lower than that for the slow phase. Moderate shortterm hypothermia led to a significant decrease of lactate dehydrogenase thermostability: thermodenaturation rate constants for the rapid (k1) and slow (k2) phases increased. Significant changes in parameters a and b reflecting the initial proportion of the two native forms of the enzyme developed only at 40°C. As hypothermia caused no appreciable changes in the energy of activation of lactate dehydrogenase denaturation, a significant contribution of the entropic factor to the decrease of free energy of enzyme denaturation was hypothesized. The data indicated significant labilization of lactate dehydrogenase structure under conditions of moderate hypothermia.
Key Wordsrats brain hypothermia lactate dehydrogenase thermostability
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- 1.Grigor’ev EV, Shukevich DL, Plotnikov GP, Tikhonov NS. Therapeutic hypothermia: the potential and prospects. Klin. Med. 2014;92(9):9-16. Russian.Google Scholar
- 2.Lutsenko DG, Marchenko VS, Sleta IV. Application of fractal analysis for complex assessment of structural and functional state of microhemocirculation in rats after whole-body hypothermia. Problemy Kriobiologii. 2008;18(3):391-393. Russian.Google Scholar
- 3.Lyubarev AE, Kurganov BI. Analysis of irreversible thermal denaturation of proteins by differential scanning calorimetry. Uspekhi Biol. Khimii. 2000;40:43-84. Russian.Google Scholar
- 5.Khalilov RA, Dzhafarova AM, Khizrieva SI. Effect of Hypothermia on Kinetic Characteristics of Lactate Dehydrogenase in Rat Brain under Conditions of Global Ischemia and Reperfusion. Bull. Exp. Biol. Med. 2017;163(3): 334-337. doi: https://doi.org/10.1007/s10517-017-3797-8 CrossRefPubMedGoogle Scholar
- 6.Blagojević D. Free radical biology in hypothermia. Systems Biology of Free Radicals and Antioxidants. Laher I, ed. Berlin; Heidelberg, 2014. P. 376-392.Google Scholar
- 8.Hochachka P, Somero G. Biochemical Adaptation. Oxford, 2002.Google Scholar
- 12.Zarisfi M, Allahtavakoli F, Hassanipour M, Khaksari M, Rezazadeh H, Allahtavakoli M, Taghavi MM. Transient brain hypothermia reduces the reperfusion injury of delayed tissue plasminogen activator and extends its therapeutic time window in a focal embolic stroke model. Brain Res. Bull. 2017;134:85-90.CrossRefGoogle Scholar