摘要：近年来，越来越多的人因为饮食上的不规律而得高血脂症，体内血脂代谢异常。因此，具有降胆固醇功效的肽的筛选和降胆固醇药物开发的相关研究备受学术界关注。本实验以蚕蛹蛋白为原料，对蚕蛹蛋白降胆固醇活性肽的制备工艺进行研究。以HMG-CoA还原酶抑制率为评价指标，筛选得到最佳蛋白酶为胰蛋白酶；分别研究了酶解温度、底物浓度、加酶量、酶解pH和酶解时间等因素对蚕蛹蛋白酶解产物HMG-CoA还原酶抑制率的影响，并在单因素的基础上，利用响应面优化其工艺条件。结果表明，各因素对制备降胆固醇活性肽的影响程度由大到小依次为底物浓度、酶解时间和酶解温度。得出制备蚕蛹蛋白降胆固醇活性肽的最优条件为：酶解pH8.0，酶浓度5000U/g，酶解温度45℃，酶解时间24.6min，底物浓度15g/L。在此条件下，抑制率理论值可达83.23%，实际抑制率为84.68%。预测模型可靠性高。

关键词：蚕蛹；酶解；HMG-CoA还原酶；降胆固醇活性；

Abstract

Because of irregular diet, more and more people got hyperlipidemia and had abnormal blood lipid metabolism in recent years. Therefore, the peptide or drug with hypocholesterolemic activities had received more attention from academic domain. In this study, technology for preparation of hypocholesterolemic peptides from silkworm pupa protein was studied. Trypsin was chosen to preparate the hypocholesterolemic peptides from silkworm pupa protein. The effects of hydrolysis temperature, substrate concentration, enzyme concentration, enzymolysis pH and enzymolysis time on HMG-CoA reductase–inhibitory activity of the hydrolysates from silkworm pupa protein were studied. On the basis of single factor, response surface was used to optimize its process conditions. The results showed that importance of the three factors affecting activity of hypocholesterolemic peptide from high to low was in the order of substrate concentration, enzymolysis time and enzymolysis temperature. The optimum conditions for the preparation  of  silkworm  pupa  protein  hypocholesterolemic  peptides  were  as   follows:

enzymolysis  pH  8.0,  enzyme  dosage  5000U  /  g,  enzymolysis  temperature  45  ℃ ,enzymolysis time 24.6 min, substrate concentration 15g / L. Under this condition, the inhibition rate for HMG-CoA reductase was 83.23% in theory and the actual inhibition rate was 84.68%. The result indicates that the established prediction model is reliable.

Keywords: silkworm pupa; enzymolysis; HMG-CoA reductase; hypocholesterolemic activity

目录

第一章绪论 1

1.1蚕蛹蛋白的制备和利用现状 2

1.1.1干蚕蛹的处理 2

1.1.2蚕蛹蛋白的提取 2

1.1.3蚕蛹蛋白的应用 3

1.1.4蚕蛹蛋白的研究现状与前景展望 4

1.2降胆固醇活性肽 5

1.2.1降胆固醇活性肽定义 5

1.2.2降胆固醇活性肽作用机制 6

1.2.3降胆固醇活性肽的制备 7

1.2.4降胆固醇肽的分离 7

1.2.5降胆固醇活性肽的测定指标 8

1.2.6发展趋势 9

1.3本实验的意义与内容 9

1.3.1研究目的 9

1.3.2研究内容