Children's Research Institute, Xi'an Key Laboratory of Children's Health and Diseases, Affiliated Children Hospital, Xi'an Jiaotong University, Xi'an 710043, Shaanxi, China.
Roosevelt University College of Pharmacy, Schaumburg, IL, USA.
J Immunol Methods. 2019 Jul;470:40-45. doi: 10.1016/j.jim.2019.04.009. Epub 2019 Apr 26.
C-reactive protein (CRP) can exist in both pentameric (pCRP) and monomeric conformation (mCRP). Though serum pCRP is an established marker of inflammation, the diagnostic significance of mCRP remains unknown largely due to the lack of a reliable assay. The power and specificity of antibody-based assays are limited by the antibody reagents used and by the degree of cross-reactivity that may exist in detecting each antigen, as mCRP is known to be formed from the pentameric and both conformations usually coexist in clinical samples. Here, we describe an assay that measures both CRP conformations in simple samples in a single assay. This assay depends on the rationale that the intra-molecular disulfide bonds in pCRP resist reduction, while those in mCRP can be readily reduced. The distinct sensitivity of pCRP and mCRP to reduction can be easily detected and separated by electrophoresis. This assay may provide a means to study clinical correlation between pCRP and mCRP in clinical samples in the future and to evaluate their respective significance as disease markers.
C 反应蛋白（CRP）可以存在五聚体（pCRP）和单体构象（mCRP）两种形式。虽然血清 pCRP 是炎症的既定标志物，但由于缺乏可靠的检测方法，mCRP 的诊断意义仍不清楚。基于抗体的检测方法的灵敏度和特异性受到所用抗体试剂的限制，以及可能存在的交叉反应程度的限制，因为众所周知 mCRP 是由五聚体形成的，并且两种构象通常在临床样本中共存。在这里，我们描述了一种在单个检测中测量简单样本中 CRP 两种构象的方法。该检测依赖于这样的原理，即 pCRP 中的分子内二硫键抵抗还原，而 mCRP 中的二硫键可以很容易地被还原。pCRP 和 mCRP 对还原的不同敏感性可以通过电泳很容易地检测和分离。该检测方法将来可能提供一种手段，以研究临床样本中 pCRP 和 mCRP 之间的临床相关性，并评估它们作为疾病标志物的各自意义。
