猪股骨头胶原蛋白降血压肽的分离纯化

依次采用碱性蛋白酶、木瓜蛋白酶和风味蛋白酶对猪股骨头胶原蛋白进行酶解，制备降血压肽。为了得到高活性、高纯度的降血压肽，依次采用超滤、离子交换层析、凝胶层析对酶解液进行分离纯化，采用体外检测方法测定各分离产物对血管紧张素转化酶活性的半抑制浓度（IC50值）。结果显示：猪骨酶解液经超滤分离获得分子质量小于5 ku的组分对血管紧张素转化酶的抑制活性最高，IC50值为1.400 2 mg/mL；该组分进行离子交换层析分离得4个组分，其中组分2的活性最高，IC50值为0.488 4 mg/mL；再将组分2进行凝胶层析分离得4 个组分，其中组分2-2的活性最高，IC50值为0.195 3 mg/mL。

Separation and Purification of Anti-hypertensive Peptides from Pig Femoral Collagen

Anti-hypertensive peptides were prepared from pig femoral bones by sequential hydrolysis using alkaline
protease, papain and flavourzyme. In order to obtain high activity and purity of anti-hypertensive peptides, ultrafiltration, ion
exchange chromatography and gel permeation chromatography were used to separate the hydrolysates. The angioensin-Ⅰ
converting enzyme (ACE) inhibitory activity (IC50) of the separated fractions was determined in vitro. The results showed
that the ultrafiltration fraction with molecular weight of less than 5 ku showed the highest ACE inhibitory activity, with an
IC50 value of 1.400 2 mg/mL. The fraction was then purified by ion exchange chromatography to obtain 4 peaks, among
which peak 2 had the strongest ACE inhibitory activity with an IC50 value of 0.488 4 mg/mL. The peak 2 was further
fractionated by gel permeation chromatography to obtain 4 sub-peaks, and the sub-peak 2-2 had the highest ACE-inhibitory
activity with an IC50 value of 0.195 3 mg/mL.