螺旋藻小分子多肽制备工艺的研究

Preparation and purification of low-molecular-weight peptides from Spirulina protein

碱性蛋白酶水解螺旋藻蛋白制备多肽粗品。根据中心组合试验设计原理,在单因素试验的基础上,以水解度为响应值,利用响应面法对影响螺旋藻蛋白水解的各种影响因素如温度、pH、酶解时间和加酶量进行了系统研究,得到最佳工艺条件为：pH值7.0、反应温度55℃、酶解时间160 min、酶底比4 300 U/g,水解度可达到26.8%。超滤截取相对分子量小于5 kD以下的组分,冷冻干燥后过SephadexG-25凝胶柱层析收集螺旋藻小分子肽段。根据标准蛋白色谱层析检测所得制品为相对分子量在307~1 450 D范围的螺旋藻小分子肽段。

Alcalase protease was used to hydrolyze the protein extracts of Spirulina to produce polypeptides.The effects of pH,enzyme dosage,hydrolysis time and temperature on degree of hydrolysis were investigated by single factor test respectively,and these factors were optimized by response surface methodology（RSM） which was designed based on Box-Behnken central combination.The optimum hydrolysis conditions were as follows： pH=7,enzyme dosage（ratio of enzyme to substrate） 4 300 U·g-1,hydrolysis temperature 55℃ and time 160 min.The hydrolysates of Spirulina protein were ultrafiltrated by 5 kD hollow fiber ultrafiltration membrane and purified by SephadexG-25 column chromatography with PBS（pH=7） as eluent.Low-molecular-weight peptides were collected,and the molecular weight was from 307 D to 1 450 D.