الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
• Benzylaminopurine and polyamines, JA, NAA and zeatin induced SOD activity.• The enzyme was purified with specific activity of 346.7 U mg-1 protein. The molecular weight was 45 KDa.• The optimal pH of the purified SOD was 7.0 and the optimal temperature was 40˚C.• BSA activated SOD activity up to 2% w/v but the higher concentration was suppressive. • Thioglycolate was activated for SOD at the lower concentrations and the optimal concentration was 60 µmol. • H2O2 and KCN were inhibitors for SOD with IC50 of 6.08 % v/v and 2.07 mM, respectively. • The optimum concentration of CaCl2 for activation of SOD was 0.6 M. • Riboflavin activated SOD activity and the optimal concentration was 0.6 M. • Sodium sulphate, sodium bromide, sodium fluoride, sodium azide and sodium arsenate inhibited SOD activity particularly sodium arsenate. • Pepsin and trypsin inhibited SOD in a concentration- dependent manner. • EDTA and α-ά-dipyridyl as chelating agent inhibited the enzyme activity. • The surfactants T60, T80 and Triton X-100 increased SOD activity and the increase was dependent on the concentrations. The thiol compounds including mercaptoethanol (ME), dithiothreitol (DTT) and reduced glutathione (GSH) activated SOD activity. • Mannitol, xylitol and trehalose offered appreciable thermostability at 60˚C. • BSA-modified enzyme and PEG-modified SOD showed appreciable thermostability at various temperatures over the optimal one (50˚C, 55˚C, 60˚C and 65˚C). • DEPC, Woodward ̓s reagent and butanedione inhibited SOD activity at the tested concentrations revealing the essentiality of histidyl, carboxyl and arginyl groups for SOD catalysis. • SOD was immobilized successfully on Ca aliginate. • It was found that 5 mg protein g-1 Ca alginate was the best protein loading for immobilization process. • The immobilized SOD was successful for 10 cycles where 52% of its activity was retained after 10 cycles. • Both CdCl2 and PbCl2 were inhibitors for SOD particularly the free enzymes.