Studies On The Interaction Between Several Active Materials And Superoxide Dismutase

Superoxide dismutase which consisted in animals, plants and microorganisms plays an important role in metabolic processes of active oxygen. The studies on the superoxide dismutase and its mimic complexes have caused extensive concern in the field of chemistry, biology and medicine. SOD can be divided into different categories according to their metal auxiliary, such as Cu/ZnSOD, Mn-SOD, Fe-SOD, Ni-SOD. The different structure between SOD lead to the differences in physical and chemical properties. This paper presents a review on the progresses of SOD studies recently, including the generation, reaction activity and the harm of superoxide anion radical as well as the types and the catalytic mechanism of the SOD. Recently, there are extensive reports on the catalytic performance of SOD. In this dissertation, we study the physical and chemical factors on the activity of CAT and Cu/Zn-SOD, the interaction of isoniazid with superoxide dismutase and Mn-SOD with a-keto isovalerate dehydrogenase. Main work as follows:1. The interaction of CAT with Cu/Zn-SODSome physical and chemical factors on the activity of CAT and Cu/Zn-SOD are discussed in this paper using the method of pyrograllol auto-oxidation. The synergy protective effect between the two enzymes was also discussed. The results show that the thermal stability, acid and alkali resistance, anti-H2O2damage of the SOD were strengthened by the synergistic protective of CAT. We also study the addition of superoxide anion radical on the activity of CAT. The results show that superoxide anion radical have a strong damage on the activity of CAT, whereas the SOD can protect it.2. The interaction of isoniazid with superoxide dismutaseThe interaction of isoniazid with superoxide dismutase(Cu-ZnSOD) was studied by ultraviolet and fluorescence spectroscopy. The results demonstrated that Cu-ZnSOD fluorescence was quenched regularly by the addition of isoniazid. Isoniazid is capable of binding with Cu-ZnSOD to form a1:1complex and the quenching mechanism of Cu-ZnSOD affected by isoniazid is a static quenching procedure by calculating the binding number and binding constant. The formation of the complex has no influence on enzyme activity. Isoniazid has the ability of superoxide anion radical scavenging.The fluorescence quenching mechanisms are also studied at different temperature. The results show that quenching mechanism is a static quenching, and interaction between isoniazid and Cu-ZnSOD is driven mainly by vander Waals and hydrophobic force.3. Properties of Mn-SOD and its interaction with a-keto isovalerate dehydrogenaseIn this section, pyrogallol autoxidation method is applied for determination the active of Mn-SOD at different temperatures, differenet pH and different concentrations of ethanol solution. We study the UV-visible absorption spectroscopy, fluorescence spectroscopy and synchronous fluorescence spectroscopy of the Mn-SOD in boric acid solution at different pH. The interaction between Mn-SOD and a-keto isovalerate dehydrogenase is studied using UV-visible absorption spectroscopy, fluorescence spectroscopy. The results show that Mn-SOD is stable to heating, showing the best activity at90oC. The acid and alkali resistance of Mn-SOD is better than Cu/ZnSOD and show the best activity at pH=11. Through investigating the UV-visible absorption spectroscopy, fluorescence spectroscopy of the Mn-SOD at different pH, we put forward that the different medium have different effects on the the tryptophan fluorescence of Mn-SOD; When the a-keto isovalerate dehydrogenase combined with Mn-SOD, the activity of Mn-SOD is significantly enhanced.