Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture, College of Pharmacy and Biological Engineering, Chengdu University , No. 1 Upper Section of Shiling Street, Chengdu 610106, P. R. China.
National R&D Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University , No. 1 Shizishan Street, Wuhan 430070, P. R. China.
J Agric Food Chem. 2017 Jul 5;65(26):5357-5364. doi: 10.1021/acs.jafc.7b01706. Epub 2017 Jun 21.
Chicken egg white (CEW) is a perfect source of natural proteins that possesses outstanding functional properties and various bioactivities. The glycosylation structure of CEW proteins plays important roles in their functions, bioactivities, and allergies. The present work attempted to identify N-glycosites of CEW proteins using an omics strategy. CEW proteins were digested with trypsin and chymotrypsin; glycopeptides were enriched and deglycosylated using PNGase F in HO water, followed by analysis using high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS). A total of 71 N-glycosites in 26 CEW glycoproteins were identified. Web-Logo analysis showed that most of the N-glycosites were at N-X-T (55%) and N-X-S (32%). Furthermore, two-dimensional electrophoresis of CEW clusterin demonstrated a series of spots horizontally distributed at 35-37 kDa with an extremely wide isoelectric point range of 4.54-6.68, indicating the heterogeneity of glycosylation of CEW clusterin. These results provided important information for the understanding of the structures, functions, and bioactivities of CEW glycoproteins.
鸡蛋白（CEW）是天然蛋白质的完美来源，具有出色的功能特性和多种生物活性。CEW 蛋白质的糖基化结构在其功能、生物活性和过敏反应中起着重要作用。本研究试图采用组学策略鉴定 CEW 蛋白质的 N-糖基化位点。用胰蛋白酶和糜蛋白酶消化 CEW 蛋白；用 HO 水中的 PNGase F 富集和去糖基化糖肽，然后用高效液相色谱/串联质谱（HPLC-MS/MS）进行分析。在 26 种 CEW 糖蛋白中鉴定出 71 个 N-糖基化位点。Web-Logo 分析表明，大多数 N-糖基化位点位于 N-X-T（55%）和 N-X-S（32%）。此外，CEW 簇蛋白的二维电泳显示一系列水平分布的斑点，在 35-37 kDa 处，等电点范围极宽，为 4.54-6.68，表明 CEW 簇蛋白的糖基化具有异质性。这些结果为理解 CEW 糖蛋白的结构、功能和生物活性提供了重要信息。
