Rakhit Rishi, Robertson Janice, Vande Velde Christine, Horne Patrick, Ruth Deborah M, Griffin Jennifer, Cleveland Don W, Cashman Neil R, Chakrabartty Avijit
Department of Biochemistry, University of Toronto and Ontario Cancer Institute, 101 College Street, Toronto, Ontario M5G 1L7, Canada.
Nat Med. 2007 Jun;13(6):754-9. doi: 10.1038/nm1559. Epub 2007 May 7.
Misfolding of Cu/Zn-superoxide dismutase (SOD1) is emerging as a mechanism underlying motor neuron degeneration in individuals with amyotrophic lateral sclerosis (ALS) who carry a mutant SOD1 gene (SOD1 ALS). Here we describe a structure-guided approach to developing an antibody that specifically recognizes monomer-misfolded forms of SOD1. We raised this antibody to an epitope that is normally buried in the SOD1 native homodimer interface. The SOD1 exposed dimer interface (SEDI) antibody recognizes only those SOD1 conformations in which the native dimer is disrupted or misfolded and thereby exposes the hydrophobic dimer interface. Using the SEDI antibody, we established the presence of monomer-misfolded SOD1 in three ALS mouse models, with G37R, G85R and G93A SOD1 mutations, and in a human individual with an A4V SOD1 mutation. Despite ubiquitous expression, misfolded SOD1 was found primarily within degenerating motor neurons. Misfolded SOD1 appeared before the onset of symptoms and decreased at the end stage of the disease, concomitant with motor neuron loss.
铜锌超氧化物歧化酶（SOD1）错误折叠正成为携带突变SOD1基因（SOD1型肌萎缩侧索硬化症，即SOD1 ALS）的肌萎缩侧索硬化症患者运动神经元变性的潜在机制。在此，我们描述了一种基于结构的方法来开发一种特异性识别SOD1单体错误折叠形式的抗体。我们针对一个通常埋藏在SOD1天然同型二聚体界面中的表位产生了这种抗体。SOD1暴露二聚体界面（SEDI）抗体仅识别那些天然二聚体被破坏或错误折叠从而暴露疏水二聚体界面的SOD1构象。使用SEDI抗体，我们在三种携带G37R、G85R和G93A SOD1突变的ALS小鼠模型以及一名携带A4V SOD1突变的人类个体中确定了单体错误折叠SOD1的存在。尽管SOD1普遍表达，但错误折叠的SOD1主要存在于退化的运动神经元内。错误折叠的SOD1在症状出现之前就已出现，并在疾病末期随着运动神经元的丧失而减少。
