鮪魚蒸煮汁之蛋白質水解物對血管張力素轉換酶的抑制活性   全文下載

Angiotensin I-Converting Enzyme Inhibitory Activity of Protein Hydrolysates from Tuna Broth

為探討由鮪魚蒸煮汁（含4%水溶性蛋白質）製備對血管張力素轉換?（angiotensin I-converting enzyme, ACE）的抑制物，運用數種蛋白質?進行研究。結果顯示orientase蛋白?水解物最具ACE抑制活性， 針對此活性的最適水解條件：50℃，pH 6.5，酵素（1.0% orientase）與受質（鮪魚蒸煮汁）的比例為1:25 （v／v），水解3小時，獲得有效的活性IC50值為12.52 ± 0.02 mg／mL。以膠過濾層析（Sephadex G-25）進行水解物蛋白質劃分，結果獲得具更高ACE抑制活性的抑制物，這些具抑制力的區分物為分子量小於1,000 Da的胜?，最具ACE抑制力的區分物之IC50值為0.21 ± 0.01 mg／mL，此區分物為小分子量的胜? （MW ＜ 656 Da），含有豐富的鹼性胺基酸、芳香族胺基酸。"

Angiotensin I-converting enzyme (ACE) inhibitors have a potent antihypertensive effect in both humans and animals. Various peptides derived from food proteins were found to have ACE inhibitory activity. For determining ACE inhibitory activity, protein hydrolysates were prepared from tuna broth (contain 4% water-soluble protein) using various commercial proteases. Orientase hydrolysate (OAH) exhibited the most potent inhibitory activity on ACE. The best hydrolysis conditions with respect to inhibition of ACE were 3hr of incubation at 50˚C, pH 6.5, with enzyme (1.0% orientase) to substrate (tuna broth) of 1/25 (v/v). Preparation under these conditions yielded activity (IC50 12.52 ± 0.02 mg/mL). Fractionation of the orientase hydrolysate on a Sephadex G-25 gel filtration chromatograph resulted in the production of more active inhibitors. The active fractions were peptides of molecular weights < 1,000 Da. The most active fraction had an IC50 value of 0.21 ± 0.01 mg/mL. This fraction was rich in basic amino acids and aromatic amino acids [peptides with molecular mass (< 565 Da)]. 為探討由鮪魚蒸煮汁（含4%水溶性蛋白質）製備對血管張力素轉換酶（angiotensin I-converting enzyme, ACE）的抑制物，運用數種蛋白質酶進行研究。結果顯示orientase蛋白酶水解物最具ACE抑制活性， 針對此活性的最適水解條件：50℃，pH 6.5，酵素（1.0% orientase）與受質（鮪魚蒸煮汁）的比例為1:25 （v／v），水解3小時，獲得有效的活性IC50值為12.52 ± 0.02 mg／mL。以膠過濾層析（Sephadex G-25）進行水解物蛋白質劃分，結果獲得具更高ACE抑制活性的抑制物，這些具抑制力的區分物為分子量小於1,000 Da的胜肽，最具ACE抑制力的區分物之IC50值為0.21 ± 0.01 mg／mL，此區分物為小分子量的胜肽 （MW ＜ 656 Da），含有豐富的鹼性胺基酸、芳香族胺基酸。