"ISOLATION, CHARACTERIZATION AND USE OF SELF-ASSEMBLING MILK-DERIVED PEPTIDES IN THE SEPARATION OF PROTEIN HYDROLYSATES"

牛奶和乳清蛋白的酶解物已被广泛用作生物活性多肽的来源(如抗高血压、免疫调节等)。然而，开发有效的提取物需要从这些水解物中浓缩甚至分离出生物活性分子我们最近的工作集中在来自β-乳球蛋白(b-LG)的一段肽，即b-Lg F1-8，它是通过反渗透浓缩b-Lg的胰酶水解物而从聚集的物质中分离出来的。这种多肽序列被发现具有自组装特性，导致在特定浓度、pH和温度下形成纳米纤维和水凝胶。在初步实验中，我们观察到蛋白质水解物与b-lg F1-8肽的纳米纤维接触可以改变其肽组成，表明这些纳米纤维可以在其表面吸附疏水性多肽。这项拟议的工作是基于这样一个研究假设，即通过诱导自组装，可以从复杂的混合物中分离出乳源性多肽。在此条件下处理的多肽混合物将表现出更好的物理化学稳定性，而自组装的多肽又可以用于多肽分离。我们研究的长期目标是开发大规模分离多肽的创新方法。更具体地说，我们的工作将集中于发展乳多肽的结构-功能特征的基础知识，这些基础知识与它们形成纳米结构的能力有关，这些纳米结构可以用作多肽分离的加工工具。这项研究计划将使用b-lg F1-8肽启动，但预计这项工作将导致从乳清蛋白中发现其他自组装肽。这一原始方法可能会为从牛奶中分离生物活性多肽等次要化合物开辟新的可能性。该研究计划将提供独特的机会来培训高素质的人员(HQP)，他们将在牛奶蛋白及其水解物和生物活性多肽的加工方面拥有深厚的背景。这项研究具有很高的潜力，可以产生对加拿大乳制品行业有用的创新。

Milk and whey protein enzymatic hydrolysates have been widely used as a source of bioactive peptides (e.g. antihypertensive, immunomodulatory, etc.). However, developing potent extracts requires that the bioactive molecules are concentrated or even separated from these hydrolysates Our recent work has focused at a peptide fragment from beta-lactoglobulin (b-LG), namely b-LG f1-8, that has been isolated from aggregated material upon concentration of a tryptic hydrolysate of b-LG by reverse osmosis. This peptide sequence was found to have self-assembling properties that leads to the formation of nanofibers and hydrogels at specific concentration, pH and temperature values. In preliminary experiments, we have observed that contacting protein hydrolysates with nanofibers of peptide b-LG f1-8 could modify their peptide composition, suggesting that these nanofibers can adsorb hydrophobic peptides on their surface. The proposed work is based on the research hypothesis that it is possible to isolate milk-derived peptides from complex mixtures by inducing self-assembly. The peptide mixture pre-treated under these conditions will exhibit improved physicochemical stability and the self-assembling peptides can in turn be used in peptide separation. The long-term objective of our research is to develop innovative approaches for the isolation of peptides at large scale. More specifically, our work will focus at developing fundamental knowledge on structure-function characteristics of milk peptides in relation with their ability to form nanostructures that can be used as processing tools in peptide separation. The research program will be initiated using peptide b-LG f1-8 but it is expected that the work will lead to the discovery of other self-assembling peptides from whey proteins. This original approach is likely to open new possibilities for the separation of minor compounds such as bioactive peptides from milk. The research program will provide unique opportunities to train highly qualified personnel (HQP) who will possess a strong background in milk proteins and their processing into hydrolysates and bioactive peptides. This research has a very high potential to generate innovations that will be useful for the Canadian dairy industry.