Molecular interaction of food-derived zinc-binding peptides with sheddases and their cellular functions

多肽，单独或作为调控蛋白的区域，可以控制许多生物过程。体内最大的外源多肽来自饮食中的蛋白质和多肽。已知几种食用肽具有控制氧化应激、炎症、血压升高和免疫功能障碍的生物学特性。然而，这些多肽表现出许多生物学效应的分子机制在很大程度上仍不清楚。我们的工作表明，锌螯合是多肽抑制锌依赖的整合素和金属蛋白酶(ADAM)17活性的部分原因，ADAM 17参与了肿瘤坏死因子的激活和体内炎症反应的启动。ADAM17和一种密切相关的蛋白质ADAM10是细胞外金属蛋白酶家族的成员，该家族被称为脱落酶，可以激活几种调节蛋白。食用肽与脱落酶的相互作用具有生物学意义，因为隔离锌的多肽可以通过肠道运输到内皮细胞和免疫细胞。在那里，这些多肽可以直接与细胞膜结合的蛋白质或它们的锌辅助因子相互作用。这项发现拨款提案侧重于了解锌结合多肽与主要的锌依赖脱落酶ADAM17和ADAM10的相互作用，这两个脱落酶分别参与炎症和血管形成。在模拟的口服/胃肠道传代后，这些多肽或它们的片段有望引起结构构象、功能和下游信号通路的变化，这些信号通路是由细胞内的脱落酶激活的。本研究的目的是(1)了解锌结合肽与脱落酶的锌辅助因子相互作用的结构基础；(2)评价锌-多肽相互作用对脱落酶功能的影响；(3)利用细胞模型阐明锌结合肽在炎症和血管形成信号通路中的分子机制。这项工作将导致对食物多肽与锌相互作用的化学基础，以及由此产生的对细胞表面脱落酶及其相关生化途径的生物学影响的重大见解。这也将支持我的研究计划的长期目标，即了解低剂量食源性多肽的机制、结构-功能关系和细胞反应。在未来五年内，该计划将支持培养10名高素质人才(2名博士、1名硕士、1名博士后S生物科学领域)。

Peptides, alone or as regions of regulatory proteins, can control many biological processes. The largest pool of external peptides in the body comes from dietary proteins and peptides. Several food peptides are known to have biological properties in controlling oxidative stress, inflammation, raised blood pressure and immune dysfunction. However, the molecular mechanisms by which the peptides exhibit many of their biological effects remain largely unknown. Our work has shown that zinc chelation is partly responsible for the activity of peptides in inhibiting a zinc-dependent “a distintegrin and metalloproteinase” (ADAM)17, which is involved in tumour necrosis factor- activation and initiation of inflammatory reactions in the body. ADAM17 and a closely related protein, ADAM10, are members of a family of extracellular metalloproteases known as sheddases, which activate several regulatory proteins. Food peptide interaction with sheddases has biological significance since peptides that sequester zinc can be transported through the intestine to endothelial and immune cells. There, the peptides can interact directly with the cell membrane-bound proteins or their zinc co-factors. This discovery grant proposal focuses on understanding the interaction of zinc-binding peptides with major zinc-dependent sheddases, ADAM17 and ADAM10, which are involved in inflammation and blood vessel formation, respectively. After simulated oral/gastrointestinal passages, the peptides or their fragments are expected to induce changes in structural conformations, functions and downstream signaling pathways activated by the sheddases in cells. The study objectives are to (1) understand the structural basis of interaction between zinc-binding peptides and zinc co-factor of sheddases; (2) evaluate the implications of the zinc-peptide interaction on the sheddase function; and (3) elucidate the molecular mechanisms of the peptides on inflammation and blood vessel formation signalling pathways using cell models. This work will lead to major insights on the chemical basis of food peptide interaction with zinc, and the resulting biological implications on cell-surface sheddases and their associated biochemical pathways. It will also support the long-term goals of my research program, which are to understand the mechanisms, structure-function relationships, and cellular response to low doses of food-derived peptides. During the next five years, the proposed program will support the training of ten highly qualified personnel (2 PhD, 1 MSc, 1 postdoctoral s bioscience sector.