基于Fe_3O_4/乙二胺四乙酸磁性粒子的集成化蛋白质组学方法

建立了基于Fe_3O_4/乙二胺四乙酸(EDTA)磁性粒子的集成化蛋白质组学研究方法。首先用共沉淀法合成EDTA负载的Fe_3O_4/EDTA磁性粒子。在优化的溶液条件下(95%乙腈-1%三氟乙酸,体积分数),100μg Fe_3O_4/EDTA磁性粒子可吸附12.4μg牛血清白蛋白(BSA),吸附容量是商品化磁珠的10倍左右。以BSA作为标准蛋白质,对所合成的Fe_3O_4/EDTA磁性粒子作为蛋白质组学反应器的酶解时间进行了优化,发现Fe_3O_4/EDTA磁性粒子处理BSA酶解1、8和16 h的肽段序列覆盖率和特征肽段结果相当。因此,可以将复杂的蛋白质样品前处理时间缩短至2 h内。最后,将所合成的Fe_3O_4/EDTA磁性粒子应用于血清的蛋白质组学研究,成功地鉴定出218种蛋白质,其中包含了41种美国食品药品管理局(FDA)认证的生物标志物。所发展的基于Fe_3O_4/EDTA磁性粒子的蛋白质组学样品前处理方法将蛋白质样品预富集、还原、烷基化、酶解、多肽除盐和洗脱等步骤集成到一起,减少了样品转移和处理所造成的损失。这种技术具有快速、灵敏和易于操作的特点,可用于临床蛋白质组学研究。

Fe3O4/ethylenediaminetetraacetic acid magnetic beads-based integrated method for proteomic analysis

A Fe₃O₄/EDTA (ethylenediaminetetraacetic acid) magnetic beads-based integrated method for proteomic analysis was developed. Fe₃O₄ magnetic beads loaded with EDTA were prepared firstly via co-precipitation method. One hundred μ g Fe₃O₄/EDTA magnetic beads could adsorb 12.4 μ g BSA (bovine serum albumin) in the optimized solution (95% acetonitrile-1% trifluoracetic acid, v/v). The binding capacity was about 10 times higher than that of the commercialized magnetic beads. The digestion time of Fe₃O₄/EDTA magnetic beads as the proteomic reactor was also optimized using BSA as the standard protein. The results indicated that the peptide coverage and unique peptides obtained from Fe₃O₄/EDTA magnetic beads with digestion time of 1, 8 and 16 h were comparable. We then applied the Fe₃O₄/EDTA magnetic beads for the serum proteome analysis. A total of 218 proteins were identified successfully, including 41 biomarkers approved by Food and Drug Administration (FDA). Protein preconcentration, reduction, alkylation, digestion, peptide desalting, and elution can be achieved in an integrated manner by the Fe₃O₄/EDTA magnetic beads-based proteomics sample preparation, which reduced the sample loss during sample transfering and processing. The developed method is fast, sensitive and easy to operate, which has prospective application for the clinic proteomics research.