Comparative Analysis of Whey Proteins in Human Milk Using a Data-Independent Acquisition Proteomics Approach during the Lactation Period

Human milk (HM) is the primary source of nutrients and bioactive components that supports the growth and development of infants. However, the proteins present in human milk may change depending on the period of lactation. In this light, the objective of the present study was to evaluate the effect of lactation period on HM utilizing a data-independent acquisition (DIA) approach to identify the differences in HM whey protein proteomes. As part of the study, whey proteins of January, February, and June in human milk were studied. The results identified a total of 1563 proteins in HM whey proteins of which 114 groups were subunits of differentially expressed proteins as revealed by cluster analysis. Protein expression was observed to be affected by the period of lactation with expression levels of plasminogen, thrombospondin-1, and tenascin higher during January, keratin, type I cytoskeletal 9 highest in February, and transcobalamin-1 highest in June. The results of this study contribute to expand our understanding of the human whey proteome but also provide strong evidence for the nutritional difference of HM during different lactation periods.

人乳（Human milk, HM）是支撑婴儿生长发育的关键营养物质与生物活性成分的主要来源。然而，人乳中含有的蛋白质会随泌乳阶段发生变化。有鉴于此，本研究旨在通过数据非依赖采集（data-independent acquisition, DIA）技术分析泌乳阶段对人乳的影响，以鉴定人乳乳清蛋白质组的差异。本研究选取了1月、2月及6月采集的人乳乳清蛋白开展分析。研究结果共鉴定出1563种人乳乳清蛋白，经聚类分析显示其中114个组为差异表达蛋白亚基。研究发现蛋白质表达水平受泌乳阶段影响：1月样本中纤溶酶原、血小板反应蛋白-1及腱糖蛋白的表达水平更高；2月样本中I型细胞骨架角蛋白9的表达水平最高；6月样本中转钴胺素-1的表达水平最高。本研究结果不仅有助于深化我们对人乳乳清蛋白质组的认知，还为不同泌乳阶段人乳的营养差异提供了有力佐证。