Cao Yong, Miao Jianyin, Liu Guo, Luo Zhen, Xia Zumeng, Liu Fei, Yao Mingfei, Cao Xiaoqiong, Sun Shengwei, Lin Yanyin, Lan Yaqi, Xiao Hang
College of Food Science, South China Agricultural University , Guangzhou 510642, People's Republic of China.
Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States.
J Agric Food Chem. 2017 Mar 22;65(11):2307-2314. doi: 10.1021/acs.jafc.6b05711. Epub 2017 Mar 8.
The ability of casein phosphopeptides (CPPs) to bind and transport minerals has been previously studied. However, the single bioactive peptides responsible for the effects of CPPs have not been identified. This study was to purify calcium-binding peptides from CPPs and to determine their effects on calcium and magnesium uptake by Caco-2 cell monolayers. Five monomer peptides designated P1 to P5 were isolated and the amino acid sequences were determined using LC-MS/MS. Compared with the CPP-free control, all five monomeric peptides exhibited significant enhancing effects on the uptake of calcium and magnesium (P < 0.05). Interestingly, when calcium and magnesium were presented simultaneously with P5, magnesium was taken up with priority over calcium in the Caco-2 cell monolayers. For example, at 180 min, the amount of transferred magnesium and calcium was 78.4 ± 0.95 μg/well and 2.56 ± 0.64 μg/well, respectively, showing a more than 30-fold difference in the amount of transport caused by P5. These results provide novel insight into the mineral transport activity of phosphopeptides obtained from casein.
酪蛋白磷酸肽（CPPs）结合和转运矿物质的能力此前已被研究。然而，导致CPPs产生这些作用的单一生物活性肽尚未被鉴定出来。本研究旨在从CPPs中纯化钙结合肽，并确定它们对Caco-2细胞单层摄取钙和镁的影响。分离出了五种命名为P1至P5的单体肽，并使用液相色谱-串联质谱法（LC-MS/MS）测定了其氨基酸序列。与不含CPPs的对照组相比，所有五种单体肽对钙和镁的摄取均表现出显著的增强作用（P < 0.05）。有趣的是，当钙和镁与P5同时存在时，在Caco-2细胞单层中，镁比钙更优先被摄取。例如，在180分钟时，转运的镁和钙的量分别为78.4±0.95μg/孔和2.56±0.64μg/孔，显示出P5引起的转运量差异超过30倍。这些结果为从酪蛋白中获得的磷酸肽的矿物质转运活性提供了新的见解。
