Wang Xuefeng, Shi Yanan, Chen Yue, Fan Jiangping, Pu Yuehong, Huang Aixiang
College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, Yunnan, China.
Biotechnology and Germplasm Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650223, China.
Food Res Int. 2020 Oct;136:109332. doi: 10.1016/j.foodres.2020.109332. Epub 2020 May 19.
This study is the first to apply label-free based proteomics to investigate the proteome changes during Moringa oleifera seed germination. In total, 1267 proteins were identified, with proteins within the molecular weight range of 10-60 kDa being most abundant. Among the 174 differentially expressed proteins (DEPs), 42 were upregulated and 26 downregulated, whereas 45 and 61 were uniquely expressed in the matured dry and germinating seeds, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the main DEPs had significant molecular functions related to catalytic activity and were involved in metabolism, degradation and biosynthesis, with 49 enzymes highly expressed in germination, including 9 proteases with hydrolytic activity, of which a peptidase and three types of endopeptidases were associated with milk-clotting activity. We further demonstrated that proteolytic activity (PA) and milk-clotting specific activity (MCSA) of protease extracts from M. oleifera seeds were increased during germination, particularly for samples from the ammonium sulfate (AS) fractionation that were statistically significance (p value < 0.05). Overall, proteases derived from germinating M. oleifera seeds can be used in the food industry, especially for potential application in the production of bioactive peptides and cheese processing.
本研究首次应用基于无标记的蛋白质组学来研究辣木籽萌发过程中的蛋白质组变化。总共鉴定出1267种蛋白质，分子量范围在10 - 60 kDa的蛋白质最为丰富。在174种差异表达蛋白（DEP）中，42种上调，26种下调，而分别有45种和61种在成熟干燥种子和萌发种子中独特表达。基因本体论（GO）和京都基因与基因组百科全书（KEGG）富集分析表明，主要的差异表达蛋白具有与催化活性相关的重要分子功能，参与代谢、降解和生物合成，有49种酶在萌发过程中高表达，包括9种具有水解活性的蛋白酶，其中一种肽酶和三种类型的内肽酶与凝乳活性相关。我们进一步证明，辣木籽蛋白酶提取物的蛋白水解活性（PA）和凝乳比活性（MCSA）在萌发过程中增加，特别是硫酸铵（AS）分级分离的样品具有统计学意义（p值 < 0.05）。总体而言，来自萌发辣木籽的蛋白酶可用于食品工业，特别是在生物活性肽生产和奶酪加工中的潜在应用。
