Laboratory of Nanomaterials, Chang Gung University, Gueishan, Taoyuan 333, Taiwan, ROC.
Anal Biochem. 2011 Nov 1;418(1):111-25. doi: 10.1016/j.ab.2011.06.018. Epub 2011 Jun 22.
Mineralo-protein nanoparticles (NPs) formed spontaneously in the body have been associated with ectopic calcifications seen in atherosclerosis, chronic degenerative diseases, and kidney stone formation. Synthetic NPs are also known to become coated with proteins when they come in contact with body fluids. Identifying the proteins found in NPs should help unravel how NPs are formed in the body and how NPs in general, be they synthetic or naturally formed, interact within the body. Here, we developed a proteomic approach based on liquid chromatography (LC) and tandem mass spectrometry (MS/MS) to determine the protein composition of carbonate-apatite NPs derived from human body fluids (serum, urine, cerebrospinal fluid, ascites, pleural effusion, and synovial fluid). LC-MS/MS provided not only an efficient and comprehensive determination of the protein constituents, but also a semiquantitative ranking of the identified proteins. Notably, the identified NP proteins mirrored the protein composition of the contacting body fluids, with albumin, fetuin-A, complement C3, α-1-antitrypsin, prothrombin, and apolipoproteins A1 and B-100 being consistently associated with the particles. Since several coagulation factors, calcification inhibitors, complement proteins, immune regulators, protease inhibitors, and lipid/molecule carriers can all become NP constituents, our results suggest that mineralo-protein complexes may interface with distinct biochemical pathways in the body depending on their protein composition. We propose that LC-MS/MS be used to characterize proteins found in both synthetic and natural NPs.
矿化蛋白纳米颗粒（NPs）在体内自发形成，与动脉粥样硬化、慢性退行性疾病和肾结石形成中观察到的异位钙化有关。当合成 NPs 与体液接触时，也已知它们会被蛋白质覆盖。确定 NPs 中存在的蛋白质应该有助于揭示 NPs 在体内是如何形成的，以及 NPs 是如何相互作用的，无论是合成的还是天然形成的。在这里，我们开发了一种基于液相色谱（LC）和串联质谱（MS/MS）的蛋白质组学方法，用于确定源自人体体液（血清、尿液、脑脊液、腹水、胸腔积液和滑液）的碳酸磷灰石 NPs 的蛋白质组成。LC-MS/MS 不仅提供了对蛋白质成分的高效和全面的测定，而且还对鉴定的蛋白质进行了半定量排序。值得注意的是，鉴定出的 NP 蛋白质反映了接触体液的蛋白质组成，白蛋白、胎球蛋白-A、补体 C3、α-1-抗胰蛋白酶、凝血酶原和载脂蛋白 A1 和 B-100 一直与颗粒有关。由于几种凝血因子、钙化抑制剂、补体蛋白、免疫调节剂、蛋白酶抑制剂和脂质/分子载体都可以成为 NP 成分，我们的结果表明，矿化蛋白复合物可能根据其蛋白质组成与体内不同的生化途径相互作用。我们建议使用 LC-MS/MS 来表征合成和天然 NPs 中发现的蛋白质。
