本研究以竹筴魚肌肉爲材料，純化出內生性組織蛋白酶B，其純化倍率、產率和分子量分別爲7，814倍、3.8%和27,500Da，利用純化的蛋白酶B水解肌動凝蛋白質，其水解產物經Shephadex G-25膠過濾層析分劃出四個分劃物，其分子量分別爲1,700、1,400、900和550Da，其血管升壓素轉換酶半抑制濃度分別爲592.6、190.3、91.6和65.8μg peptide/ml，本研究結果顯示竹筴魚肌肉蛋白質經組織蛋白酶B水解後的產物具有血管升壓素轉換酶抑制活性，未來將可應用於降高血壓機能性食品的開發。

The study was to purify cathepsin B from horse mackerel (Trachurus japonicus) and fractionate the angiotensin I-converting enzyme (ACE) inhibitory peptides from catheptic hydrolysates. The purification fold, yield and molecular weight of horse mackerel cathepsin B were 7,814 fold, 3.8% and 27,500Da respectively. Four fractions with ACE-inhibitory activity appeared on Shephadex G-25 chromatography. Their molecular weight were 1,700, 1,400, 900and 550Da respectively. The IC50 of four hydrolysates were 592.6, 190.3, 91.6 and 65.8μg peptide/ml. The results suggest that horse mackerel protein hydrolysates by cathepsin B might be a potential ingredient for the formulation of hypotensive functional foods.