Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011-1061, USA.
J Sci Food Agric. 2012 Dec;92(15):3095-8. doi: 10.1002/jsfa.5778. Epub 2012 Jul 6.
Egg phosvitin could be a good source of functional peptides. Enzymatic dephosphorylation and high-pressure processing combined with thermal treatment applied before proteolysis could produce phosvitin hydrolysates with different properties compared to its native form.
Phosvitin structure was maintained overall during high-pressure treatment of 600 MPa applied at an initial temperature of 65 °C regardless of the pH and duration of treatment, confirming the high structural stability of this phosphoprotein. Treatment of phosvitin with phosphatase increased the degree of dephosphorylation from 24% to 63%, after 2 and 18 h, respectively. Moderate dephosphorylation of phosvitin prior to proteolytic digestion improved its hydrolysis, allowing formation of peptides with a molecular weight lower than 17,000 kDa as determined by size exclusion chromatography. Angiotensin-converting enzyme (ACE) inhibition and antioxidant activity of dephosphorylated and protease-treated phosvitin was increased by 52% and 39%, respectively, as compared to protease-digested native phosvitin.
Enzymatic dephosphorylation before proteolysis mimicking in vivo gut conditions improved ACE inhibition and antioxidant activity of phosvitin hydrolysates.
卵黄高磷蛋白可以作为功能性肽的良好来源。酶法脱磷酸化和高压处理与热处理相结合，应用于蛋白水解之前，可以产生与天然形式相比具有不同特性的卵黄高磷蛋白水解产物。
在初始温度为 65°C 时，应用 600 MPa 的高压处理，卵黄高磷蛋白的结构在整个过程中得到了保持，无论处理的 pH 值和时间如何，这证实了这种磷蛋白具有很高的结构稳定性。用磷酸酶处理卵黄高磷蛋白后，分别在 2 小时和 18 小时时，其磷酸化程度从 24%增加到 63%。在酶解消化之前进行适度的脱磷酸化可以改善其水解作用，使分子量低于 17000 kDa 的肽得以形成，这是通过排阻色谱法确定的。与经蛋白酶消化的天然卵黄高磷蛋白相比，脱磷酸化和经蛋白酶处理的卵黄高磷蛋白的血管紧张素转化酶（ACE）抑制率和抗氧化活性分别提高了 52%和 39%。
在模拟体内肠道条件下进行酶法脱磷酸化，然后进行蛋白水解，可以提高卵黄高磷蛋白水解产物的 ACE 抑制率和抗氧化活性。
