酶解蓝圆鲹蛋白制备降血压肽的工艺研究

Study on technology of antihypertensive peptides production from Decapterus maruadsi protein with enzymatic hydrolysis

以蓝圆鲹(Decapterus maruadsi)鱼肉蛋白为原料,选用6种蛋白酶在各自适宜的条件下酶解制备降血压肽,通过检测酶解产物对血管紧张素转化酶(ACE)的体外抑制活性,筛选出木瓜蛋白酶为制备蓝圆鲹降血压肽的最佳用酶。考察了不同水解度的酶解产物对ACE抑制效果,当水解度为13.7%时,产物对ACE的最高抑制活性可达67.4%。在此基础上,分别了考察酶解时间、初始酶用量、初始底物浓度、酶解温度和pH值对酶解工艺的影响,得到制备蓝圆鲹降血压肽的适宜酶解工艺为:初始酶用量为7000 U/g,初始底物浓度为25 g/L,酶解温度为45℃,pH为7.0,酶解240 min。采用超滤技术对酶解产物活性组分进行分离富集,发现产物中高活性部分均可富集于10 kDa和5kDa渗透液中,且高活性组分分子量主要集中在5 kDa以下,该组分对ACE的活性抑制率为88.47%。

The protein from Decapterus maruadsi was hydrolyzed by six different proteolytic enzymes in their optional conditions. The inhibition percent （IP） of Angiotensin I-converting enzyme （ACE） by the hydrolysates was examined with high performance liquid chromatography. Results showed the papain was the best enzyme for producing ACEI. When the degree of hydrolysis （DH） was 13.7%, the inhibition of ACE by the hydrolysate reached as high as 67.4%. Further on, the influence of hydrolysis time, initial enzyme concentrations （[E]）, initial substrate concentrations （[S]）, hydrolysis temperatures and pH values was investigated. Results showed that the optimal condition for producing ACEI was as follows： [E] at 7000 U/g.Pro, IS] at 25 g/L, hydrolysis temperature at 45 ℃, pH at 7.0 and hydrolysis time in 240 minutes. Then ultrafiltration technology was used to separate and enrich the active part of hydrolysates. Results showed that the higher active part of the hydrolysates can be enriched in the penetrating fluid of both 10 and 5 KDa. It was also found that the higher active hydrolysates were mainly lower than 5 KDa with an ACE inhibition rate of 88.47%.