Highly efficient separation, enrichment, and recovery of peptides by silica-supported polyethylenimine.
Highly efficient separation, enrichment, and recovery of peptides by silica-supported polyethylenimine.
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DOI：
10.1021/la502093k
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发表时间：
2014-10
期刊：
影响因子：
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通讯作者：
Feng Chen;Decheng Wan;Zhihong Chang;H. Pu;M. Jin
中科院分区：
文献类型：
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作者：
Feng Chen;Decheng Wan;Zhihong Chang;H. Pu;M. Jin
描述了固相吸附剂对多肽在痕量水平上的高效和电荷选择性吸附和解吸。通过将支化的聚乙烯亚胺(PEI)固定在多孔二氧化硅颗粒(∼300μm)的外表面，合成了SiO_2@PEI的吸附剂。对于相对分子质量为600-3000 Da的水基多肽，SiO_2@PEI可以捕获带负电荷的多肽，而不带正电荷的多肽，通过调节体系的pH值，可以很好地分离不同等电点的多肽。低丰度的目标肽(相对于最高丰度的多肽至少低至0.1mol%)可以很好地分离。通常可以得到K>；10(12)M(-1)在pH>；pI和K10(8)下的缔合常数。因此，即使是亚毫微克分子水平的多肽也可以被提取和洗脱用于分析，并且多肽的有效回收率(79-92%)被发现。PEI在低pH条件下的亲水性和阳离子性质对解吸效率和选择性起着独特的作用。这种方法的无偏特性使该吸附剂适用于有效分离广谱多肽，包括那些具有类似PI S的多肽。
Highly efficient and charge-selective adsorption and desorption of peptides at trace level by a solid-phase adsorbent is described. The adsorbent of SiO2@PEI is synthesized by covalent immobilization of branched polyethylenimines (PEI) exclusively on the outer surface of the porous silica particles (∼300 μm). For aqueous peptides (Mw = 600-3000 Da), SiO2@PEI can capture the negatively charged ones and leave the positively charged ones intact, and by adjusting pH of the system peptides with different isoelectric points (pIs) can be well separated. Targeted peptide at low abundance (at least as low as 0.1 mol % with respect to the highest one) can be well separated. The association constants of K > 10(12) M(-1) at pH > pI and K 10(8) is generally available. Thus, a peptide even at sub-femtomolar level can be extracted and eluted for analysis, and efficient recovery (79-92%) of the peptides is found. The extraction is mainly promoted by multisite electrostatic interaction, and the hydrophilic and cationic properties of PEI at low pH play a unique role in desorption efficiency and selectivity. The unbiased nature of this method renders the adsorbent applicable to the efficient separation of a broad spectrum of peptides, including those with similar pIs.