Department of Electronic Engineering, Universitat Rovira i Virgili, Tarragona, Spain.
Anal Bioanal Chem. 2012 Mar;402(7):2407-15. doi: 10.1007/s00216-011-5705-9.
The sizes of certain types of lipoprotein particles have been associated with an increased risk of cardiovascular disease. However, there is currently no gold standard technique for the determination of this parameter. Here, we propose an analytical procedure to measure lipoprotein particles sizes using diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY). The method was tested on six lipoprotein fractions, VLDL, IDL, LDL1, LDL2, HDL2, and HDL3, which were obtained by sequential ultracentrifugation from four patients. We performed a pulsed-field gradient experiment on each fraction to obtain a mean diffusion coefficient, and then determined the apparent hydrodynamic radius using the Stokes–Einstein equation. To validate the hydrodynamic radii obtained, the particle size distribution of these lipoprotein fractions was also measured using transmission electron microscopy (TEM). The standard errors of duplicate measurements of diffusion coefficient ranged from 0.5% to 1.3%, confirming the repeatability of the technique. The coefficient of determination between the hydrodynamic radii and the TEM-derived mean particle size was r2 = 0.96, and the agreement between the two techniques was 85%. Thus, DOSY experiments have proved to be accurate and reliable for estimating lipoprotein particle sizes.
某些类型的脂蛋白颗粒的大小与心血管疾病风险的增加有关。然而，目前还没有用于确定这一参数的金标准技术。在这里，我们提出了一种使用扩散排序核磁共振波谱法（DOSY）测量脂蛋白颗粒大小的分析程序。该方法在通过连续超速离心从四名患者中获得的六个脂蛋白级分（VLDL、IDL、LDL1、LDL2、HDL2 和 HDL3）上进行了测试。我们对每个级分进行了脉冲场梯度实验，以获得平均扩散系数，然后使用 Stokes-Einstein 方程确定表观水动力半径。为了验证所获得的水动力半径，还使用透射电子显微镜（TEM）测量了这些脂蛋白级分的粒径分布。扩散系数重复测量的标准误差范围为 0.5%至 1.3%，证实了该技术的可重复性。水动力半径和 TEM 衍生的平均粒径之间的决定系数 r2 为 0.96，两种技术之间的一致性为 85%。因此，DOSY 实验已被证明是准确可靠的，可以用于估计脂蛋白颗粒的大小。
