Vecchi B, Añón M C
Centro de Investigación y Desarrollo en Criotecnología de Alimentos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CP 1900, La Plata, Argentina.
Phytochemistry. 2009 May;70(7):864-70. doi: 10.1016/j.phytochem.2009.04.006. Epub 2009 May 13.
Amaranth seed is a valuable source of dietary protein with very high nutritional quality, and recently its potential as a nutraceutical has been proposed. The aim of this work was to provide experimental evidence for the presence of anti-hypertensive peptides in globulin 11S, one of the major constituents of the seed, by means of an in-silico based peptide library screening method. A three-dimensional model of globulin 11S was built, upon which anti-hypertensive peptides were mapped via a database-driven method. Solvent accessibility was evaluated for each potential peptide, and two potent and exposed tripeptides were detected: IKP and LEP. An N-terminal extension of these two peptides was built using the globulin 11S primary sequence information, and ACE inhibitory behaviour was simulated by automated ligand-protein docking. The occurrence of two inhibitory tetrapeptides, ALEP and VIKP, was predicted and experimentally validated by an in vitro ACE inhibition assay that showed IC50 values of 6.32 mM and 175 microM, respectively. This study is the first to provide experimental proof of the anti-hypertensive value of Amaranth. Furthermore, this is the first time that a peptide docking approach is used to find ACE-inhibitory peptides from a food protein source.
苋菜籽是一种具有极高营养价值的膳食蛋白质宝贵来源，最近有人提出了其作为营养保健品的潜力。这项工作的目的是通过基于计算机模拟的肽库筛选方法，为种子的主要成分之一球蛋白11S中存在抗高血压肽提供实验证据。构建了球蛋白11S的三维模型，并通过数据库驱动的方法在该模型上绘制抗高血压肽。评估了每个潜在肽的溶剂可及性，检测到两种有效且暴露的三肽：IKP和LEP。利用球蛋白11S的一级序列信息构建了这两种肽的N端延伸，并通过自动配体-蛋白质对接模拟了ACE抑制行为。预测了两种抑制性四肽ALEP和VIKP的存在，并通过体外ACE抑制试验进行了实验验证，该试验显示IC50值分别为6.32 mM和175 microM。本研究首次提供了苋菜籽抗高血压价值的实验证据。此外，这是首次使用肽对接方法从食物蛋白来源中寻找ACE抑制肽。
