Lee Su Jin, Youn Byung-Soo, Park Ji Woo, Niazi Javed H, Kim Yeon Seok, Gu Man Bock
School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-701, Korea.
Anal Chem. 2008 Apr 15;80(8):2867-73. doi: 10.1021/ac800050a. Epub 2008 Mar 7.
Retinol binding protein 4 (RBP4) is a useful biomarker in the diagnosis of type 2 diabetes since its level in the serum is higher in insulin-resistant states. Accurate measurement of the serum RBP4 levels is hampered by conventional immunologic methods, such as enzyme-linked immunosorbent assay (ELISA). In this study, therefore, we have developed an aptamer-based surface plasmon resonance (SPR) biosensor that can be used to sense for RBP4 in serum samples. A single-stranded DNA (ssDNA) aptamer that showed high affinity (Kd = 0.2 +/- 0.03 microM) and specificity to RBP4 was selected. This RBP4-specific aptamer was immobilized on a gold chip and used in a label-free RBP4 detection using SPR. Analysis of RBP4 in artificial serum using SPR was compared with ELISA and Western blot analysis. Our results indicated that the RBP4-specific aptamer-based SPR biosensor gave better dose-dependent responses and was more sensitive than ELISA assays. As such, this RBP4 aptamer-based SPR biosensor can be potentially used to monitor the RBP4 levels within the serum as an indicator of type 2 diabetes.
视黄醇结合蛋白4（RBP4）是诊断2型糖尿病的一种有用生物标志物，因为在胰岛素抵抗状态下其血清水平较高。传统免疫方法，如酶联免疫吸附测定（ELISA），阻碍了血清RBP4水平的准确测量。因此，在本研究中，我们开发了一种基于适体的表面等离子体共振（SPR）生物传感器，可用于检测血清样本中的RBP4。筛选出了对RBP4具有高亲和力（解离常数Kd = 0.2±0.03 microM）和特异性的单链DNA（ssDNA）适体。将这种RBP4特异性适体固定在金芯片上，并用于基于SPR的无标记RBP4检测。使用SPR对人工血清中的RBP4进行分析，并与ELISA和蛋白质印迹分析进行比较。我们的结果表明，基于RBP4特异性适体的SPR生物传感器具有更好的剂量依赖性反应，并且比ELISA检测更灵敏。因此，这种基于RBP4适体的SPR生物传感器可潜在地用于监测血清中的RBP4水平，作为2型糖尿病的一个指标。
