| It is well known that most carbohydrates in food is starch. Amylase in saliva, pancreas can decompose starch into maltose in short time, which is absorbed by alvine in the form of glucose. The inhibitors of a-amylase extracted from wheat flour has more powerful inhibition function than that from beans. It is found that primary purified, sufficient a-amylase inhibitors can inhibit the amylase activity in pancreas secreted from alvine, block or deter it's digestion for starch which mainly composed by carbohydrates. Thus the blood sugar and blood fatty are decreased and the rise of blood sugar concentration is inhibited, which is benefited the therapy of diabetic. To adiposity patient, the enzyme can decrease the conversion of sugar to fat, and block the exclude of alvine, increase the consume of fat which help lose weight. So, a-amylase inhibitor can be used to prevent and treat adiposity , lipomatosis, atherosclerosis, hyperlipidemia and diabetes. Besides, amylase inhibitor extracted from microorganism or beans have strong inhibit function to a-amylase in enteron of insects, especially for the insect which feed on wheat. The inhibitor can decrease the diet of the insect, or even made them fast, then play the function of pesticide. So, a-amylase inhibitor has great potential to produce newly bio-pesticide. Its toxicity is much lower than traditional pesticides, and it also has little pollution to the environment. Considering the great biology function of a-amylase inhibitor, many researchers did a great deal of studies on extraction technics, structures, properties, and pharmacology of a-amylase inhibitor from different resources. But in these references, there are few which has great referenced value of industrialize for a-amylase inhibitor. So, in this paper, studies were carried out to research on extraction of a-amylase inhibitor with the methods of aqueous two-phase system and large aperture iron exchange pitch. A new technic was reached to lay a foundation for a-amylase inhibitors' industrialization.After many researches, it was found that the traditional aqueous two-phase system, such as PEG/sulphate or PEG/phosphate can not effectively separatea-amylase from other proteins. So, a strong-hydrophile salt, fructose-1,6-diphosphate(FDP) was usedto take place of sulphate or phosphate. A new type of aqueous two-phase system was designed, that is PEG/FDP sodium salt. This system was used to extract a-amylase inhibitor, and the result was perfect.1 Use PEG6000 to get phase-polymer is superior to PEG 1000. Confecting a mixed solution in which the concentration of phased PEG 1000 and PEG6000 was the same, the total concentration was 50%. So the concentration of the PEG1000 and PEG6000 were all 25%. Keep the total concentration of PEG in system is 5%, then adjusted the percent of these two kinds of PEG in the mixed solution, when the concentration of PEG6000 in system rised from the total PEG's 25% to 50%, the specific activity Sa raised from 1.28 times to 2.45 times.2 With the concentration of PEG6000 rised in a certain range, both extractive efficiency Ea and specific activity Sa increased first then decreased. When the concentration of PEG increased from 2.75% to 3.47%, the Ea increased from 77.82% to 80.68%, and Sa increased from 2.24times to 2.31 times; when the concentration of PEG increase from 3.47% to 10.1%, the Sa decrease from 2.31 times to 1.53 times. And yield decrease from 80.68% to 73.56%; but when PEG concentration increased to 16.82%, Sa decreased dramatically to 0.41 times, and the yield decreased to 23%.3 when pH value is above 4 , properly decreasing of pH can benefit the extraction. It was found that when pH value decreased from 7.44 to 4.32, the Sa increased from 1.12 times to 2.44 times. Ea increased from 79.67% to 83.56%.4 properly increasing of FDP can benefit to improve the purification times. It was found that when the concentration of FDP sodium increased from 20% to 23%, Sa increased from 2.32 to 2.65 times, when the concentration of FDP sodium increased continuously to 26%, not only Sa had no evident increase but also Ea decreased sharply instead.5 adding NaCl could decline purification times and extraction effect. During the process, along with the slowly increasing of NaCl to 6%, Ea decreased from 81.30% to 58.70%, and Sa decreased from 2.41 times to 0.85 times.6 Finally, the optimum operation process was determined as the concentration of PEG6000 was about 3.47%, the concentration of FDP sodium salt was about 23%,and pH was close to 4. the inhibit activity could be improved 2.65 times and the yield could achieved 78.82%.The traditional protein chromatography medium was mainly Sephadex, Sepharose and DEAE Sephacel. These medium must work under high pressure, and the medium and facility were much expensive. In this paper, the common larger aperture ion exchange pitch was first time used to separate a-amylase inhibitor. The studies indicated that common large aperture pitch can be used for the separation of a-amylase inhibitor. The result was as followings:1 Through static state experiment, it was found that the absorbance volume of D315 pitch to a-amylase inhibitor was above 6000U/g.resin, elute rate was above 76.25%, can be used for separation of a-amylase inhibitor.2 through dynamic experiment, it was found that the optimum absorb condition for a-amylase inhibitor on D315 is: sample protein concentration is 2.5mg/ml |
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