Production of functional peptides from livestock and fish waste

开发了利用含有胶原蛋白的骨头、皮肤、海鲷鱼鳞等家畜和鱼类废弃物生产功能性食品的工艺。选择了16种商业酶来评价它们对含胶原蛋白废物的降解效果。水解产物具有较强的抗自由基活性（ipox <50>， 0.18和0.45 mg/ml）和较强的降血压潜能（ipox <50>， 0.46和0.71 mg/ml）。进一步研究了其IC50为0.57 mg/ml的鲷鱼鳞水解液。对自发性高血压大鼠，口服300 mg /（kg体重）/d可显著降低血压（p<0.05）。采用凝胶过滤层析（Sephadex LH-20）、阴离子交换层析（UNO Q-1）、凝胶过滤层析（Superdex Peptide HR 10/30）和反相层析（Sephasil Peptide C18柱），从水蛭水解液中分离出4个具有高血管紧张素I转换酶（ACE）抑制活性的肽段。反相色谱法分离得到的4种多肽的ACE抑制活性比未纯化的水解产物高5 ~ 20倍。抑制肽的氨基酸序列确定为Gly-Tyr、Val-Tyr、Gly-Phe和Val-Ile-Tyr；此外，合成Val-Ile-Tyr和Val-Tyr具有较高的ACE抑制活性，IC_<50>值分别为7.5 μM和16 μM。肽的c端氨基酸是酪氨酸和苯丙氨酸，对ACE活性位点的底物结合起着最重要的作用。

A procedure for the production of functional food from livestock and fish waste such as bone, skin, and sea bream scales containing collagen was developed. Sixteen commercial enzymes were selected to evaluate their effectiveness for degradation of the waste containing collagen. The hydrolysates had a high anti-radical activity (IPOX_<50>, 0.18 and 0.45 mg/ml) and a high potential for decreasing blood pressure (IC_<50>, 0.46 and 0.71 mg/ml). The hydrolysate from sea bream scales, of which IC50 was 0.57 mg/ml was further studied. Using spontaneously hypertensive rats, oral administration of 300 mg of the peptides/(kg of body weight)/d was shown to significantly (p<0.05) decrease blood pressure. Four peptides that demonstrated high angiotensin I converting enzyme (ACE) inhibitory activities were isolated from the hydrolysate of the scales using chromatographic methods using gel filtration chromatography (Sephadex LH-20), anion-exchange chromatography (UNO Q-1), gel filtration chromatography (Superdex Peptide HR 10/30), and reverse-phase chromatography (Sephasil Peptide C18 column). The ACE inhibitory activities of the four peptides isolated by reverse-phase chromatography were 5 to 20 times higher than that of the unpurified hydrolysate. The amino acid sequences of inhibitory peptides ware determined to Gly-Tyr, Val-Tyr, Gly-Phe and Val-Ile-Tyr; furthermore, synthetic Val-Ile-Tyr and Val-Tyr demonstrated high ACE inhibitory activities with IC_<50> values of 7.5 μM and 16 μM, respectively. The C-terminal amino acid of the peptides, that is most important contribution to substrate binding at the ACE active site, were tyrosine and phenylalanine.