酶法制备鱼降血压肽的工艺优化及其组分分析

为了开发鲬鱼蛋白,以体外血管紧张素转换酶(ACE)抑制率为指标,通过适宜酶酶解鲬鱼蛋白质制备降血压活性肽。根据供试酶的水解进程筛选适宜水解酶,在单因素试验的基础上,采用响应面分析法优化水解条件,凝胶过滤层析法测定活性肽相对分子质量分布。结果表明,Alcalase是供试酶中最适的水解酶,最优水解条件为:温度48.9℃,pH7.93,加酶量为32396.6 U/g·pro,固液比1:5 g/mL,水解时间2.5 h。在此条件下,酶解液的ACE抑制率IC₅₀=0.269 mg/mL;酶解物经Sephadex G-15凝胶过滤层析得到三个组分,相对分子质量分别为635、258、67,其中的2号组分(C=0.74 mg/mL) ACE抑制活性相对较高,达到89.09%。

Optimization of Preparation of Hypotensive Peptide from Platycephalus Indicus by Enzymatic Method and Its Component Analysis

In order to exploit the proteins from Platycephalus indicus, the preparation technology of peptides with Angiotensin converting enzyme (ACE) inhibition activity by hydrolyzing protein from Platycephalus indicus enzymatcally using ACE inhibition model in vitro as index was studied.The suitable enzyme was selected according to the hydrolysis process of tested enzymes.The key factors were examined by single factor experiment. The optimal hydrolysis condition was established using respond surface methodology. The relative molecular weight distribution of active peptides was determined by gel filtration chromatography.Results showed that Alcalase was the suitable enzyme for hydrolyzing proteins from Platycephalus indicus to prepare peptides with ACE inhibition activity.The optimal hydrolysis condition were as follows:temperature of 48.9℃, pH of 7.93, the amount of enzyme was 32396.6 U/g·pro.And solid-liquid ratio was 1:5 (g/mL), duration time was 2.5 h.The IC₅₀ of hydrolysate prepared under these conditions was 0.269 mg/mL. Three fractions were obtained when applying hydrolysate on Sephadex G-15 column, the relative molecular masses were 635, 258 and 67.The ACE inhibition activity of fraction 2 (C=0.74 mg/mL) was relative higher than the others, reaching 89.09%.