玉米低聚肽中焦谷氨酰亮氨酸(pEL)二肽的研究

Study on pEL dipeptide in corn oligopeptides

考察了玉米低聚肽的理化组成成分,由于制备玉米低聚肽的原料玉米蛋白氨基酸序列独特,含有较多的谷氨酰胺及亮氨酸,且大多以相邻的位置存在,研究重点考察了玉米低聚肽中具有抗抑郁活性的肽段焦谷氨酰亮氨酸(pyroGlu-Leu,pEL)二肽结构。结果表明,玉米低聚肽蛋白含量高,干基蛋白含量为87.70%,肽含量为82.76%,平均分子质量为461.20 Da,且分子质量集中在140~1000 Da。所有氨基酸中谷氨酸(谷氨酰胺)含量最高为21.76%,其次为亮氨酸,含量为12.79%,并且亮氨酸是含量最高的必需氨基酸。结构研究结果表明,玉米肽中存在pEL二肽,含量为0.58%以上,且在5个批次玉米低聚肽样品中含量稳定。此研究可为玉米低聚肽作为新型功能食品的开发提供理论依据。

The physical and chemical composition of corn oligopeptides was investigated in this study.Due to the unique amino acid sequence of corn protein which with high amount of glutamine and leucine and exist in adjacent positions,this study also focused on the pyroglutamyl-leucine(pyroGlu-Leu,pEL)dipeptide structure with antidepressant activity from corn oligopeptide.The results showed that corn oligopeptide had high protein content which reached 87.70%,and the peptide content was 82.76%.The average molecular weight was 461.20 Da and mainly in the range of 140-1000 Da.The highest content of all amino acids was glutamic acid(glutamine)which reached 21.76%,followed by leucine with a content of 12.79%and leucine was the highest essential amino acid.The results of structural studies indicated that the content of pEL was more than 0.58%in corn oligopeptides,and it was stable in five batches of corn oligopeptide samples.This research provides a theoretical basis for developing corn oligopeptide as a new functional food.