Document Details
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Document Type |
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Thesis |
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Document Title |
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Characterization of α-amylase from miswak (salvadora persica) خواص أنزيمات الألفا- أميليز من المسواك (سالفادورا بيرسيكا) |
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Subject |
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Biochemistry department |
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Document Language |
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Arabic |
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Abstract |
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Amylases (EC 3.2.1.1) are a class of hydrolases widely distributed in microbes, plants and animals. They can specifically cleave the O-glycosidic bonds in starch. This study focused on the extraction, purification and characterization of α-amylase from miswak tree for detecting the suitable conditions for using this enzyme in toothpaste in the future.
The purification method included chromatography of α-amylase on DEAE-Sepharose column and Sephacryl S-200 column.
The miswak α-amylases A1, A4a, A4b, A5a and A5b had molecular weights of 14, 74, 16, 30 and 20 kDa, respectively using gel filtration and SDS-PAGE. Miswak α-amylases had optimum pH from 6 to 8. Affinity of the substrates toward all enzymes was studied. Miswak α-amylases had Km values for hydrolyzing potato soluble starch and glycogen of 3.7, 3.7, 7.1, 0.52, 4.3 mg/0.5 ml and 5.95, 5.9 4.16, 6.3, 6.49 mg/0.5 ml, with catalytic efficiencies (Vmaxs) of 0.71, 0.60, 1.36, 0.37, 0.71 and 1.04, 0.03, 0.25, 0.16, 0.15 μmol reducing sugar/0.5 ml, respectively. The optimum temperature for five enzymes ranged 40˚C- 60˚C. Miswak α-amylases were stable up to 40°C- 60˚C after incubation for 30 min. All the examined metal cations showed different activation/inhibition effects on the activity of miswak α-amylases. The metal chelators, EDTA, sodium citrate and sodium oxalate had inhibitory effects on miswak α-amylases. PMSF and 1,10 phenanthroline caused slightly inhibitory effect on amylases A1, A4a and A4b and partially inhibitory effect on A5a and A5b. α-amylases A1, A4a and A5b were strongly inhibited, whereas A4b and A5a were partially inhibited by p-HMB. DTNB caused partially inhibitory effect on the enzymes A1, A4a, A4b and A5b while caused slightly inhibitory effect on the A5a. |
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Supervisor |
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Dr. Saleh Ahmed Mohamed |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1434 AH
2013 AD |
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Co-Supervisor |
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Dr.Youssri Mohamed Ahmed Soliman |
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Added Date |
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Tuesday, January 15, 2013 |
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Researchers
| ياسر قائد المليكي | Almulaiky, Yaaser Qaaed | Researcher | Master | |
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