Zoltewicz J Susie, Scharf Dancia, Yang Boxuan, Chawla Aarti, Newsom Kimberly J, Fang Lijuan
Banyan Biomarkers Inc., Alachua, Florida, USA.
Biomark Insights. 2012;7:71-9. doi: 10.4137/BMI.S9873. Epub 2012 Jun 25.
After traumatic brain injury (TBI), glial fibrillary acidic protein (GFAP) and other brain-derived proteins and their breakdown products are released into biofluids such as CSF and blood. Recently, a sandwich ELISA was constructed that measured GFAP concentrations in CSF or serum from human mild-moderate TBI patients. The goals of the present study were to characterize the same two antibodies used in this ELISA, and to determine which GFAP bands are detected by this antibody combination. Here, both antibodies recognized GFAP specifically in human brain and post-TBI CSF in a cluster of bands ranging from 50-38 kDa, that resembled bands from calpain-cleaved GFAP. By immunoprecipitation, the anti-GFAP Capture antibody recovered full length GFAP and its breakdown products from human brain lysate and post-TBI CSF. These findings demonstrate that the anti-GFAP ELISA antibodies non-preferentially detect intact GFAP and GFAP breakdown products, underscoring their utility for detecting brain injury in human patients.
创伤性脑损伤（TBI）后，胶质纤维酸性蛋白（GFAP）及其他脑源性蛋白及其分解产物会释放到脑脊液（CSF）和血液等生物流体中。最近，构建了一种夹心酶联免疫吸附测定法（ELISA），用于测量人类轻度至中度TBI患者脑脊液或血清中的GFAP浓度。本研究的目的是鉴定该ELISA中使用的两种相同抗体，并确定该抗体组合能检测出哪些GFAP条带。在此，两种抗体均能在人脑中以及TBI后的脑脊液中特异性识别GFAP，其条带集中在50 - 38 kDa范围内，类似于钙蛋白酶裂解的GFAP条带。通过免疫沉淀法，抗GFAP捕获抗体从人脑裂解液和TBI后的脑脊液中回收了全长GFAP及其分解产物。这些发现表明，抗GFAP ELISA抗体能非选择性地检测完整的GFAP和GFAP分解产物，突出了它们在检测人类患者脑损伤方面的实用性。
