State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang, Jiangxi 330047, China.
J Agric Food Chem. 2014 Mar 26;62(12):2522-30. doi: 10.1021/jf5002765. Epub 2014 Mar 14.
The glycation extent of bovine serum albumin (BSA) before and after ultrasonication was evaluated by MALDI-TOF and Orbitrap mass spectrometry. Ultrasonic pretreatment significantly improved the incorporation of galactose to BSA. Prior to ultrasonic pretreatment, only 12 sites (11 lysines and 1 arginine) were glycated, whereas the number of glycation sites was increased to 42, including 39 lysines and 3 arginines, after treatment. Average degree of substitution per peptide molecule of BSA (DSP) was used to evaluate the glycation level for each glycation site. The ultrasonic pretreatment significantly improved the DSP value of all glycation sites. The prevalently promoted glycation by ultrasonic pretreatment suggests that ultrasonication improves glycation through altering the structure of BSA throughout all three domains. An ultrahigh-resolution linear ion trap Orbitrap mass spectrometer facilitates unambiguous localization of glycation sites, allowing an in-depth analysis of the nature and extent of protein glycation at the molecular level. High-intensity ultrasonication can greatly improve protein glycation and, therefore, opens new routes to modify the functionality of proteins in a positive way.
采用 MALDI-TOF 和 Orbitrap 质谱法评价超声处理前后牛血清白蛋白（BSA）的糖基化程度。超声预处理显著提高了半乳糖与 BSA 的结合。预处理前，只有 12 个位点（11 个赖氨酸和 1 个精氨酸）发生糖基化，而处理后糖基化位点增加到 42 个，包括 39 个赖氨酸和 3 个精氨酸。BSA 每个肽分子的平均取代度（DSP）用于评估每个糖基化位点的糖基化水平。超声预处理显著提高了所有糖基化位点的 DSP 值。超声预处理显著促进糖基化，表明超声通过改变 BSA 所有三个结构域的结构来改善糖基化。超高分辨率线性离子阱 Orbitrap 质谱仪可明确确定糖基化位点的位置，从而在分子水平上深入分析蛋白质糖基化的性质和程度。高强度超声处理可以大大提高蛋白质的糖基化程度，因此为以积极的方式修饰蛋白质的功能开辟了新途径。
