A shotgun proteomic study of the protein corona associated with cholesterol and atheronal-B surface-modified quantum dots

Abstract

As part of ongoing research in our group, we are keen to monitor the protein binding and movement of sterols and oxysterols in biological systems in real time. However, prior to performing these in vivo studies, we have herein studied how sterol and oxysterol surface modification of quantum dots affects their associated protein coronas. Thus, we have synthesized and analyzed cholesterol and atheronal-B surface-modified quantum dots (termed QD-chol and QD-ath-B, respectively). The fluorescence properties and aggregation propensities of QD-chol and QD-ath-B are unchanged relative to amino-functionalized quantum dots (QD-NH(2)) in aqueous buffers. Shotgun proteomic analyses of the protein coronas reveal that QD-ath-B and QD-chol are bound significantly higher to LDL, vLDL and HDL particles than QD-NH(2). Thus, almost all the component proteins of the HDL and LDL proteomes are elevated in the protein coronas around the QD-chol and QD-ath-B nanomaterials. In addition, the reduced positive surface charge of the QD-chol and QD-ath-B materials, relative to QD-NH(2), means that hydrophobic antibody light chain fragments and β-2-glycoprotein (apo H) bind them preferentially to QD-NH(2).