Plasma Fractionation and Mixture Improves Coverage in Proteomic Analysis

Expanding plasma proteome coverage increases the success
in proteomic
discovery of blood biomarkers. Here we report that the sequential
precipitation of plasma by increasing concentrations of acetonitrile
(AcN) can fractionate proteins. Combining some of these fractions
with other fractions from polyethylene glycol (PEG) precipitation
and albumin depletion to have the mixed sample that included these
partitioned fractions: 10% whole plasma, 20% 20%-AcN-pellet, 10% 40%-AcN-pellet,
20% 50%-AcN-supernatant, 20% 10%-PEG-precipitation-albumin-depletion,
and 20% 20%-PEG-precipitation-albumin-depletion, has yielded identification
of 5441 proteins, remarkably larger than the 2040 proteins detected
in the whole plasma directly. This study provides nearly the largest
plasma proteomics data sets and recommends this fractionation and
mixture strategy as an efficient approach for expanded plasma proteomics
coverage.

扩大血浆蛋白质组（plasma proteome）的覆盖范围，可提升血液生物标志物的蛋白质组学发现成功率。本研究报道，通过逐步提升乙腈（Acetonitrile, AcN）浓度对血浆进行连续沉淀，能够实现蛋白质的分级分离。将部分此类分级组分与聚乙二醇（PEG）沉淀及白蛋白去除法所得的其他组分混合，得到包含以下分区组分的混合样本：10%全血浆、20% 20%乙腈沉淀组分、10% 40%乙腈沉淀组分、20% 50%乙腈上清液、20% 10%聚乙二醇沉淀-白蛋白去除组分，以及20% 20%聚乙二醇沉淀-白蛋白去除组分。最终该样本可鉴定出5441种蛋白质，其数量显著高于直接检测全血浆时检出的2040种蛋白质。本研究构建了目前规模接近最大的血浆蛋白质组数据集，并推荐该分级混合策略作为拓展血浆蛋白质组覆盖范围的高效手段。