Production of functional peptides from livestock and fish waste

开发了一种从畜禽和鱼的下脚料中生产功能食品的方法，如含有胶原蛋白的骨、皮和海鳗鳞片。选择了16种商用酶来评价它们对含胶原蛋白废物的降解效果。水解物具有较高的抗自由基活性(IPOX；50和0.45 mg/ml)和较高的降压潜力(IC_(50)和0.71 mg/ml)。进一步研究了罗非鱼鳞片的水解液，其IC50为0.57 mg/ml。在自发性高血压大鼠中，口服300 mg/(kg体重)/d的多肽可显著降低血压(p&lt；0.05)。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 Peptic HR 10/30)和反相色谱(Sephasil PepticC18)等方法从鱼鳞水解液中分离得到4个具有较高血管紧张素转换酶(ACE)抑制活性的多肽。经反相层析分离得到的4种多肽的ACE抑制活性比未纯化的水解物高5~20倍。合成的Val-Ile-Tyr、Val-Tyr、Gly-Phe和Val-Ile-Tyr具有较高的血管紧张素转换酶抑制活性，IC_(50)和IC_(50)分别为7.5μM和16μM。多肽的C端氨基酸是酪氨酸和苯丙氨酸，这是对ACE活性部位底物结合贡献最大的氨基酸。

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.