Facile synthesis of copper(II)-decorated functional mesoporous material for specific adsorption of histidine-rich proteins

Abstract

The Cu2+-decorated functional mesoporous material was fabricated by thermally initiated free-radical polymerization of octavinyl polyhedral oligomeric silsesquioxane. It was used as adsorbent for highly specific separation of histidine (His)-rich proteins in blood and cell lysate based on immobilized metal affinity chromatography. The functional mesoporous material (named as PPOSS-IDA-Cu2+) was characterized in detail and its selectivity and binding capacity were evaluated using a His-rich protein (bovine hemoglobin, BHb) and other proteins (bovine serum albumin, myoglobin, lysozyme and horseradish peroxidase) containing fewer surface-exposed His residues as model proteins. The results indicated that PPOSS-IDA-Cu2+ exhibited large specific surface area and good selective adsorption ability and the maximum adsorption capacity for BHb was 3150mgg−1. Moreover, PPOSS-IDA-Cu2+ had excellent recyclability and the adsorption capacity of the reused material for BHb remained almost unchanged after six cycles. In addition, PPOSS-IDA-Cu2+ not only showed excellent performance for the removal of highly abundant hemoglobin in human blood, but also can be a good adsorbent for the enrichment of proteins in cell lysate. It was the first time to explore the application of Cu2+-decorated functional material as an adsorbant for the separation of proteins in cell lysate. This approach can be combined with other techniques which can remove or deplete highly abundant proteins from real biological samples to obtain more comprehensive data about low abundant His-rich proteins in proteomic analysis.