Tu Maolin, Liu Hanxiong, Cheng Shuzhen, Xu Zhe, Wang Li-Shu, Du Ming
School of Food Science and Technology, National Engineering Research Center of Seafood, Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, Liaoning 116034, China.
Division of Hematology and Oncology, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Food Res Int. 2020 Dec;138(Pt A):109764. doi: 10.1016/j.foodres.2020.109764. Epub 2020 Oct 2.
Casein is an excellent source for producing anticoagulant and angiotensin I-converting enzyme inhibitory (ACEI) peptides. Here, the anticoagulant and ACEI activities of the casein hydrolysate produced by in vitro simulated gastrointestinal (GI) digestion were evaluated. The casein hydrolysate showed potent anticoagulant activity by prolonging the thrombin time (TT) and activated partial thromboplastin time (APTT), and also presenting great ACEI activity, with an IC value of 0.52 mg mL. Subsequently, the transepithelial transport properties of the casein hydrolysate were analyzed by using the Caco-2 cell monolayer model. The peptides profile of the casein hydrolysate before and after it passed across the Caco-2 cell monolayer were identified by NanoLC-Q-TOF-MS/MS. The results showed that a total of 121 and 184 peptides were identified before and after casein hydrolysate moved through the Caco-2 cell monolayer, respectively. Eighty peptides were presented at both time points of the transport study. Among the 80 peptides, 26 of them were screened with a high possibility of exerting physiological roles after they were absorbed into the blood by in silico methods, and the physicochemical characteristics, e.g., hydrophobicity, net charge, and toxicity of the peptides also be evaluated. Our results provided a new prospect and approach for producing bioactive peptides from casein with anticoagulant and ACEI activities.
酪蛋白是生产抗凝血剂和血管紧张素I转换酶抑制（ACEI）肽的优质来源。在此，对体外模拟胃肠道（GI）消化产生的酪蛋白水解物的抗凝血和ACEI活性进行了评估。酪蛋白水解物通过延长凝血酶时间（TT）和活化部分凝血活酶时间（APTT）表现出强大的抗凝血活性，并且还呈现出很强的ACEI活性，IC值为0.52 mg/mL。随后，使用Caco-2细胞单层模型分析了酪蛋白水解物的跨上皮转运特性。通过NanoLC-Q-TOF-MS/MS鉴定了酪蛋白水解物穿过Caco-2细胞单层前后的肽谱。结果表明，酪蛋白水解物穿过Caco-2细胞单层之前和之后分别鉴定出总共121种和184种肽。在转运研究的两个时间点均出现了80种肽。在这80种肽中，通过计算机方法筛选出26种在被吸收进入血液后极有可能发挥生理作用的肽，并且还评估了这些肽的物理化学特性，例如疏水性、净电荷和毒性。我们的结果为从酪蛋白生产具有抗凝血和ACEI活性的生物活性肽提供了新的前景和方法。
