Zilin Wang, Ruijing Gu, Yu Zhou, Qimin Xie, Chengjie Liu, Na Zhou, Yang Tian, Qianqian Ouyang, Liang Tao
This study aimed to address the poor bioavailability of traditional calcium supplements by investigating the Moringa oleifera Lam. leaf-derived peptide KTFQGPPHG and its peptide-calcium chelate. Virtual screening predicted potential interactions of KTFQGPPHG with Ca2+ and calcium transport-related proteins, including TRPV6, Cav1.3, and PepT1. During simulated digestion, KTFQGPPHG-Ca showed high intestinal-phase stability, with a calcium retention rate of 94.13 ± 1.47%, while its major digestive fragment, TFQGPPHG, retained substantial calcium-binding activity. In Caco-2 cell monolayers, both KTFQGPPHG-Ca and TFQGPPHG-Ca significantly enhanced calcium transport compared with CaCl2, with Cav1.3 and TRPV6 being major pathways involved in this process. Proteomic analysis suggested that these chelates may regulate calcium absorption-associated epithelial pathways, including "cell adhesion molecules" and "ECM-receptor interaction," which may contribute to epithelial barrier integrity and cell-matrix signaling associated with Ca2+ transport. In conclusion, KTFQGPPHG-Ca exhibits high gastrointestinal stability and enhances calcium transport through multiple pathways, supporting its potential development as a novel calcium supplement.