Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 210023 China.
Department of Food Science and Technology, School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 210023 China; Food and Pharmaceutical Sciences College, Ningbo University, 315800 China.
J Dairy Sci. 2020 May;103(5):3924-3936. doi: 10.3168/jds.2019-17586. Epub 2020 Feb 26.
This study sought to assess the cholesterol-lowering activity of peptides obtained from milk casein hydrolyzed with neutrase. The bioactive peptides were separated using a Sephadex G-10 chromatographic column (Amersham Pharmacia Biotech, Uppsala, Sweden) after ultrafiltration using a 1-kDa molecular mass cutoff membrane. Via ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, we determined that peptides Thr-Asp-Val-Glu-Asn [TDVEN; β-casein f(143-147)], Leu-Gln-Pro-Glu [LQPE; β-casein f(103-106)], Val-Ala-Pro-Phe-Pro-Glu [VAPFPE; α-casein f(40-45)], and Val-Leu-Pro-Val-Pro-Gln [VLPVPQ β-casein f(185-190)] reduced micellar cholesterol solubility. After Caco-2 cells were treated with LQPE, VLPVPQ, and VAPFPE, the Niemann-Pick C1-Like 1 (NPC1L1) protein levels decreased by (means ± SEM) 19.33 ± 2.47%, 52.1 ± 3.77%, and 23.09 ± 8.52%, respectively, compared with the control group. Treatment with each peptide induced significant upregulation of ATP binding cassette subfamily G member 8 antibody (ABCG8) mRNA expression by 398.1 ± 23.27%, 86.4 ± 27.07%, and 92.8 ± 8.49%. We found that VLPVPQ and LQPE significantly upregulated ATP-binding cassette transporter A1 (ABCA1) transcription by 203.9 ± 8.44% and 220.8 ± 36.42% respectively, whereas VLPVPQ significantly decreased mRNA expression of acetyl-CoA-acetyltransferase 2 (ACAT2) and microsomal triacylglycerols (MTP). The cholesterol-lowering action of milk-derived peptides may be induced by suppression of micellar cholesterol solubility and affects the expression of cholesterol absorption-related proteins and enzymes in intestinal epithelial cells. This research discovers new milk-derived peptides with decreasing cholesterol micellar solubility and provides a theoretical basis of in vitro cholesterol-lowering effects of peptides.
本研究旨在评估中性蛋白酶水解乳清蛋白得到的肽的降胆固醇活性。生物活性肽经 1kDa 分子量截留膜超滤后，用 Sephadex G-10 色谱柱（Amersham Pharmacia Biotech，瑞典 Uppsala）分离。通过超高效液相色谱-电喷雾串联质谱法，我们确定肽 Thr-Asp-Val-Glu-Asn [TDVEN；β-酪蛋白 f(143-147)]、Leu-Gln-Pro-Glu [LQPE；β-酪蛋白 f(103-106)]、Val-Ala-Pro-Phe-Pro-Glu [VAPFPE；α-酪蛋白 f(40-45)]和 Val-Leu-Pro-Val-Pro-Gln [VLPVPQ；β-酪蛋白 f(185-190)]降低了胶束胆固醇的溶解度。用 LQPE、VLPVPQ 和 VAPFPE 处理 Caco-2 细胞后，Niemann-Pick C1-Like 1（NPC1L1）蛋白水平分别比对照组降低 19.33±2.47%、52.1±3.77%和 23.09±8.52%。用每种肽处理后，ABCG8 抗体 mRNA 表达分别显著上调 398.1±23.27%、86.4±27.07%和 92.8±8.49%。我们发现，VLPVPQ 和 LQPE 分别显著上调 ABCA1 转录 203.9±8.44%和 220.8±36.42%，而 VLPVPQ 显著降低了乙酰辅酶 A-乙酰转移酶 2（ACAT2）和微粒体三酰甘油（MTP）的 mRNA 表达。乳源肽的降胆固醇作用可能是通过抑制胶束胆固醇的溶解度诱导的，并影响肠上皮细胞中胆固醇吸收相关蛋白和酶的表达。本研究发现了具有降低胆固醇胶束溶解度的新的乳源肽，为肽的体外降胆固醇作用提供了理论依据。
