Department of Experimental Veterinary Science, University of Padua, Viale dell'Università, Legnaro, Padua, Italy.
Mol Nutr Food Res. 2010 Oct;54(10):1428-35. doi: 10.1002/mnfr.200900443.
Although the bioavailability of large peptides with biological activity is of great interest, the intestinal transport has been described for peptides up to only nine residues. β-casein (β-CN, 193-209) is a long and hydrophobic peptide composed of 17 amino acid residues (molecular mass 1881 Da) with immunomodulatory activity. The present work examined the transport of the β-CN (193-209) peptide across Caco-2 cell monolayer. In addition, we evaluated the possible routes of the β-CN (193-209) peptide transport, using selective inhibitors of the different routes for peptide transfer through the intestinal barrier. The results showed that the β-CN (193-209) peptide resisted the action of brush-border membrane peptidases, and that it was transported through the Caco-2 cell monolayer. The main route involved in transepithelial transport of the β-CN (193-209) peptide was transcytosis via internalized vesicles, although the paracellular transport via tight-junctions could not be excluded. Our results demonstrated the transport of an intact long-chain bioactive peptide in an in vitro model of intestinal epithelium, as an important step to prove the evidence for bioavailability of this peptide.
尽管具有生物活性的大肽的生物利用度非常重要，但目前仅描述了多达九个残基的肽的肠道转运。β-酪蛋白（β-CN，193-209）是一种由 17 个氨基酸残基组成的长而疏水的肽，具有免疫调节活性。本研究检测了 β-CN（193-209）肽在 Caco-2 细胞单层中的转运。此外，我们使用不同途径的选择性抑制剂评估了 β-CN（193-209）肽转运的可能途径，这些抑制剂用于通过肠道屏障转移肽。结果表明，β-CN（193-209）肽抵抗了刷状缘膜肽酶的作用，并通过 Caco-2 细胞单层进行转运。β-CN（193-209）肽跨上皮转运的主要途径是通过内吞小泡的转胞吞作用，尽管不能排除通过紧密连接的旁细胞转运。我们的结果证明了完整的长链生物活性肽在肠道上皮体外模型中的转运，这是证明该肽生物利用度的重要步骤。
